WO1995004718A1

WO1995004718A1 - 4-methyleneproline derivatives as fungicides

Info

Publication number: WO1995004718A1
Application number: PCT/GB1994/001497
Authority: WO
Inventors: John Michael Cox; David Philip John Pearson; Anthony Marian Kozakiewicz; David Youle; William Guy Whittingham; Stephen Paul Heaney
Original assignee: Zeneca Limited
Priority date: 1993-08-04
Filing date: 1994-07-11
Publication date: 1995-02-16
Also published as: IL110308A0; GB9413861D0; ZA945259B; AU7129394A; GB9316162D0

Abstract

A fungicidal composition comprising a fungicidally effective amount of a compound of formula (I), wherein R is OH, optionally substituted alkoxy, optionally substituted phenoxy, optionally substituted phenylalkoxy, alkenyloxy, NR<5>R<6> (wherein R<5> and R<6> are, independently, hydrogen, optionally substituted alkyl, optionally substituted phenyl or optionally substituted phenylalkyl) or a nitrogen atom which is included in a peptide residue; or a salt thereof, and a fungicidally acceptable carrier or diluent therefor.

Description


  
 



   4-METHYLENEPROLINE DERIVATIVES AS FUNGICIDES
 The present invention relates to fungicidal compositions comprising 4-methyleneproline derivatives, to the use of said compositions and derivatives in combating fungi (especially fungal infections of plants) and to certain 4-methyleneproline derivatives and process for preparing them.



   4-Methylene-DL-proline is a naturally occurring racemic amino acid that can be isolated from loquat seed   FEriobotrva      japonica;    see Nature   AQA    388-9 (1964), ibid   193    1285-6 (1962) and Phytochemistry   ii    745-50 (1972)].



  It is known that 4-methyleneproline inhibits the growth of the roots of
Phaseolus aureus seedlings [Journal of Experimental Botany   14    387-98 (1963)].



   According to the present invention there is provided a fungicidal composition comprising a fungicidally effective amount of a compound of formula (I) wherein R is OH, optionally substituted alkoxy, optionally substituted phenoxy, optionally substituted phenylalkoxy, alkenyloxy, NR5R6 (wherein R5 and R6 are, independently, hydrogen, optionally substituted alkyl, optionally substituted phenyl or optionally substituted phenylalkyl), or a nitrogen atom which is included in a peptide residue; or a salt thereof; and a fungicidally acceptable carrier or diluent therefor.



   Alkyl groups and the alkyl part of alkoxy, phenylalkyl and phenylalkoxy groups are straight or branched chains and contain (unless otherwise stated) preferably from 1 to 10, especially from 1 to 6 (such as from 1 to 4) carbon atoms. Alkyl is, for example, methyl, ethyl or n- or iso-propyl.



   It is preferred that.alkyl and alkoxy groups, and the alkoxy part of phenylalkoxy, are optionally substituted by halogen,   C16    alkoxy,   C16    haloalkoxy,   C16      alkoxy(C1 6)alkoxy    or phenylalkoxy   (in    which the phenyl group is optionally substituted).



   The alkenyl part of the alkenyloxy group is a straight or branch chain having, preferably, up to three double bonds and preferably containing from 3 to 20 carbon atoms. Alkenyl is, for example, allyl, but-2-enyl or farnesyl.



   Phenyl groups and the phenyl part of phenylalkyl, phenoxy and phenylalkoxy are optionally substituted, and are preferably substituted with one or more of halogen, hydroxy, C1-6 alkyl, C1-6 alkoxy,   C16     haloalkyl,   C16    haloalkoxy, nitro, cyano, phenyl or halophenyl.



   As the 2 position of the ring of the compounds of formula (I) is not symmetrically substituted, the compounds of formula (I) can exist as either (D) or (L) (that is either   (B)    or (S) respectively) isomers and, unless otherwise stated, a reference to a compound of formula (I) includes the (D) and (L) isomers individually and mixtures of these isomers in all proportions. The (L) (that is the (S)) isomers of compounds of formula (I) form a preferred embodiment of the present invention.



   Peptide residues include glycine, alanine, valine, leucine, isoleucine, serine, threonine, cysteine, methionine, phenylalanine, tyrosine, lysine or norvaline.



   Salts of a compound of formula (I), when in the form of an acid, ester or amide, include salts of a mineral or an organic acid (for example, a hydrochloride, acetate, hydrobromide, hydroiodide, trifluoroacetate, sulphate, nitrate, oxalate, malonate, fumarate or citrate) or, when R is
OH, an alkali metal, alkaline earth metal or amine salt of the acid.



   In one aspect the present invention provides a fungicidal composition comprising a fungicidally effective amount of a compound of formula (I) wherein R is OH, optionally substituted alkoxy, optionally substituted phenoxy, optionally substituted phenylalkoxy or alkenyloxy; or a salt thereof; and a fungicidally acceptable carrier or diluent therefor.



   In another aspect the present invention provides a fungicidal composition comprising a fungicidally effective amount of a compound of formula (I) wherein R is OH or unsubstituted   C16    alkoxy; or a salt thereof; and a fungicidally acceptable carrier or diluent therefor.



   In a further aspect the present invention provides a fungicidal composition comprising a fungicidally effective amount of a compound of formula (I) as hereinbefore defined, wherein the compound of formula (I) is the (L) (that is the   (±))    isomer; or a salt therof; and a fungicidally acceptable carrier or diluent therefor.



   In a still further aspect the present invention provides a fungicidal composition comprising a fungicidally effective amount of a compound of formula (I) wherein R is OH, methoxy or ethoxy; the compound of formula (I) being the (L) (that is the (S)) isomer; or a salt (such as the hydrochloride) salt thereof; and a fungicidally acceptable carrier or diluent therefor.  



   In another aspect the present invention provides a fungicidal composition comprising a fungicidally effective amount of the hydrochloride salt of a compound of formula (I) as hereinbefore defined; and a fungicidally acceptable carrier or diluent therefor.



   It is preferred that the composition of the present invention comprises 4-methylene-(L)-proline as a fungicidal active ingredient.



   In one aspect the present invention provides a method of combating fungi which comprises applying to plants, to seeds of plants or to the locus of the plants or seeds a compound of formula (I) or a composition, both as hereinbefore defined.



   In another aspect the present invention provides a compound of formula (I) wherein R is OH, optionally substituted alkoxy, optionally substituted phenoxy, optionally substituted phenylalkoxy, alkenyloxy, NR5R6 (wherein R5 and R6 are, independently, hydrogen, optionally substituted alkyl1 optionally substituted phenyl or optionally substituted phenylalkyl), or a nitrogen atom which is included in a peptide residue; or a salt thereof; provided that when R is OH the compound is in the form of a salt, but not a hydrochloride salt, and that when R is methoxy and the compound is in the L configuration then the compound is in the form of a salt, but not a hydrochloride salt.



   In a further aspect the present invention provides a compound of formula (I) wherein R is OH, optionally substituted alkoxy, optionally substituted phenoxy, optionally substituted phenylalkoxy or alkenyloxy, or a salt thereof; provided that when R is OH the compound is in the form of a salt, but not a hydrochloride salt, and that when R is methoxy and the compound is in the L configuration then the compound is in the form of a salt, but not a hydrochloride salt.

 

   In a still further aspect the present invention provides a compound of formula (I) wherein R is unsubstituted   C26    alkoxy, or a salt thereof.



   In another aspect the present invention provides a salt of a compound of formula (I) wherein R is OH or methoxy, provided that the salt is not a hydrochloride salt.



   In a further aspect-the present invention provides a salt of a compound of formula (I) wherein R is OH, the compound being the (L) (that is the (S)) isomer.



   In a still further aspect the present invention provides a salt of a  compound of formula (I) wherein R is methoxy, the compound being the (L) (that is the (S)) isomer; provided that it is not a hydrochloride salt.



   The composition of the present invention preferably comprises a compound of formula (I) as described in Tables I, II or III.



   TABLE I
Compounds listed in Table I are of formula (I).



   Compound R mpt ( C) Comments
 No.



   1 OH 229 2S (that is L)
 2 OH 233 2B (that is D)
 3 OH 2R:2S (1:1)
 4   OCH3   
 5 OCH3 2R
 6 OCH3 2R:2S
 7 farnesyloxy 2S
 8 farnesyloxy    2B   
 9 farnesyloxy   oxy   
 10 OCH3 150-152   2S,HCl    salt
 11 OCH2CH3
 12 OnPr
 13   OiPr    gum 2S, TFA salt
 14 OnBu
 15 oiBu   2i   
 16   otBu 2S   
 17 O-n-Pentyl
 18 O-n-Hexyl
 19 O-n-Heptyl
 20   O-ff-Octyl 2S   
 21 O-n-Nonyl 2S
 22 O-n-Decyl gum 2S, TFA salt
 23 O-n-Undecyl
 24 O-n-Dodecyl
 25 OCH2CF3  
Compound R mpt ( C) Comments
No.



  26 OCH2C 27   OCH2OCH3    28 OCH2OCH2C 29 OAllyl 30 0-2-Butenyl 31 0-3-Butenyl 32 O-(2-Methylallyl) 33 O-(3,3-Dimethylall
 34 O-Geranyl 2S 35 O-Cinnamyl 2S 36   OCH2CH2C6H5    37 OCH2CH2 38 OCH2CH2 39 OCH2CF2   40 0-(3-Methyl-3-butenyl) 2S    41 OC6H5 42 O-(2-F-C6H4) 43 O-(2-CF3-C6H 44 O-(2-C1-C6H4 45 O-(2-OCH3-C6 46   O-(2-CH3-C6H4)    47 O-(2-NO2-C6H 48 O-(3-F-C6H4) 49 O-(3-CF3-C6H 50 O-(3-Cl-C6H4 51 O-(3-OCH3-C6 52 O-(3-CH3-C6H 53 O-(3-NO2-C6H 54 O-(4-F-C6H4) 55 O-(4-CF3-C6H 56 O-(4-Cl-C6H4  
Compound R mpt ( C) Comments
No.



  57 O-(4-OCH3-C6H4 58 O-(4-CH3-C3-C6 59 O-(4-NO2-C6H4 60 O-(3,6-di-F-C6 61   O-(2,6-di-Cl-C6H3)    62 O-(3,5-di-CF3-C6H 63 O-(3,5-di-F-C6H3) 64 O-(3,5-di-OCH3-C6 65 O-(2,4-di-CH3-C6H 66 O-(2,4-di-CH3-C6H 67 O-(2-CH3-4-F-C6H3 68 O-(2-F-4-Cl-C6H3) 69 O-(2-Cl-4-F-C6H3) 70 O-(3-Cl-5-OCH3-C6 71   OCH2C6H5    gum 72 OCH2-(2-F-C6 73   OCH2-(2-CF3-C6H4)    74 OCH2-(2-F-C6 75   OCH2-(2-Cl-C6H4) 2S    76 OCH2-(2-OCH3-C6 77 OCH2-(2-NO2-C6H 78 OCH2-(3-F-C6H4) 79 OCH2-(3-CF3-C6H 80 OCH2-(3-F-C6H4) 81 OCH2-(3-Cl-C6H4 82 OCH2-(3-OCH3-C6 83 OCH2-(3-NO2-C6H 84 OCH2-(4-F-C6H4) 85 OCH2-(4-CF3-C6H 86 OCH2-(4-F-C6H4) 87 OCH2-(4-Cl-C6H4  
 Compound R mpt ( C) Comments
 No.



   88 OCH2-(4-OCH3-C6H4)
 89 OCH2-(4-NO2-C6H4)
 90 OCH2-(2,6-di-F-C6H3)
 91 0CH2-(2,6-di-Cl-C6H3)
 92 OCH2-(3,5-di-F-C6H3)
 93 OCH2-(3,5-di-CF3-C6H3)
 94 OCH2-(3,5-di-OCH3-C6H3)
 95 CH2-(3,4-di-Cl-C6H3)
 95 OCH2-(3,4-di-Cl-C6H3)
 96 OCH2-(2,4-di-Cl-C6H3)
 97   OCH2-(2,4-di-CH3-C6H3) 2S   
 98 OCH2-(2-Cl-6-F-C6H3)
 99   OCH2-(1-Naphthalenyl)   
 100 OCH2-(2-Naphtahalenyl)
 101 OCH(CH3)C6H5
 102   OCH(CH3)-(2-CF3-C6H4) 2i   
 103 OCH(CH3)-(3-CF3-C6H4)   
 104 OCH(CH3)-(4-CF3-C6H4)
 TABLE 11   
Compounds listed in Table II are of formula (Ia)
Compound R1 R2   mpt( C)    Comments
 No.



   1 H H oil
 2 CH3 H oil
 3   CH2CH3    H
 4 npr H
 5 iPr H
 6 nBu H  
Compound R1 R2 mpt( C) Comments
 No.



   7 iBu H
 8 tBu H
 9 CH2C6H5 H
 10 C6H5 H
 11 CH3 CH3 oil
 12 CH2CH3 CH2CH3
 13 nPr nPr
 14 iPr iPr
 15 nBu nBu
 16 iBu iBu
 17 CH2C6H5 CH2C6H5
 18 CH3 CH2CH3
 19 CH2CH3 iPr
 20 CH3 CH2C6H5
 TABLE III
 Compounds listed in Table III are of formula (I).



  Compound R mpt ( C) Comments
 No.



   1 gly
 2 ala
 3 norvaline
 4 val
 5 leu
 6 ile
 7 ser
 8 thr
 9 norleucine
 10 sarcosine  
Compound R mpt ( C) Comments
No.



   11 lys
 12 asp
 13 glu
 14 met
 15
 16 asn
 17
 18 arg
 19 his
 20 phe
 21 tyr
 22 phenylglycine
 23 gly-gly
 24 ala-ala gum 2S, TFA salt
 25 leu-ala
 26 ala-norvaline
 27 gly-leu
 28 gly-glu
 29 glu-glu
 30 ala
 31 glu-phe
 32 asp-phe
 33 ala-ala
 34 gly-gly-gly-gly
 The following abbreviations have been used throughout the Tables :

  :
   n Pr    = n-propyl
 Pr = iso-propyl
 nBu-n-bu
   Bu    = iso-butyl
 tBu-tert-bu  
 TFA = trifluoroacetate
 gly = N-linked glycine
 ala =   linked    alanine
 val =   linked    valine
 leu = N-1liked leucine
 ile =   linked    isoleucine
 ser =   linked    serine
 thr = N-linked threonine
 lys = lysine linked through   nitrogen   
 asp = N-linked aspartic acid
 glu =   linked    glutamic acid
 met = N-linked methionine
 cys = N-linked cysteine
 asn = N-linked asparagine
   gln    = glutamine linked through   &alpha;

  ;-nitrogen   
 arg = N-linked arginine
 his = N-linked histidine
 phe = N-linked phenylalanine
 tyr = N-linked tyrosine
 TABLE IV
 Table IV shows selected proton NMR data for certain compounds described in the Tables above. Chemical shifts are measured in ppm from tetramethylsilane. Unless otherwise stated, spectra were recorded on an instrument operating at 270 MHz. The following abbreviations are used
 s = singlet d = doublet
 t = triplet m = multiplet
 q = quartet dd = double doublet
 br = broad ppm = parts per million  
 Compound No 1H NMR (solvent)
 13 (CDCl3) 5.23(2H,d), 5.12(1H,m), 4.52(1H,m),   4.06(2H,br    s), (Table I) 3.13(1H,br d), 2.84(1H,br d), 1.28(6H,m)ppm.



   22 (CDCl3)   10.08(1H,br    s), 8.11(1H,br s), 5.24(2H,d),4.60(1H,dd) (Table I) 4.23(1H,m), 4.10(2H,br s), 3.16(1H,dd), 2.88(1H,dd),
   1.66(2H,m),    1.27(14H,m),   0.89(3H,t)ppm.   



   71 (CDCl3) 7.35(5H,m),   5.22(2H,q),    5.18(2H,m), 4.58(1H,dd), 4.01 (Table I) (2H,m), 3.10(1H,dd), 2.84(1H,dd)ppm.



   1   (CD3OD)    5.21(2H,m),4.45(1H,t),   4.00(2H,q),3.15(1H,dd),    (Table II) 2.84(1H,m)ppm.



   2   (CD3OD)    5.21(2H,m), 4.37(1H,t),   3.98(2H,q),3.23(1H,dd),    (Table II)   2.90(3H,s),    2.80(1H,m)ppm.



   11 (CD30D) 5.23(2H,m), 4.81(1H,t), 4.00(2H,q), (Table II) 3.23(1H,dd), 3.08(3H,s), 3.00(3H,s), 2.65(1H,m)ppm.



   24 (CD30D) 5.28(2H,br s), 4.42(3H,m),   4.01(2H,q),    3.15(1H,dd), (Table III) 2.80(1H,dd), 1.40(6H,d)ppm.



   A compound of formula (I), wherein R is OH, can be prepared by the method shown in Scheme I.



   A compound of formula (I), wherein R is OH, can be prepared by deprotecting a compound of formula   (II),    wherein R' is an alkoxycarbonyl group or arylalkoxycarbonyl group or other suitable protecting group. For example, when R' is a tert-butoxycarbonyl group or benzyloxycarbonyl group deprotection can be effected by contacting the compound of formula   (II)    with a suitable acid (such as 85% aqueous formic acid).

 

   A compound of formula (II) can be prepared by contacting a compound of formula (III), wherein R' is as defined above, with a mixture of methyltriphenylphosphonium bromide and a suitable base (such as sodium hydride) in a suitable solvent (such as an ethereal solvent, for example tetrahydrofuran).



   A compound of formula (III) can be prepared by oxidising a compound of formula (IV) using a suitable oxidising agent (such as chromium trioxide) in a suitable solvent (such as a mixture of pyridine and dichloromethane).  



   A compound of formula (IV) can be prepared using standard literature methods (for example M. Itoh, D. Hagiwara and T. Kamiya, Bull. Chem. Soc.



  Japan (1977)   fiQ    718) for protecting the ring nitrogen of 4-hydroxy-2pyrrolidine carboxylic acid.



   Alternatively a compound of formula (I), wherein R is hydroxy, can be prepared by the process described in Tetrahedron 48(31) 6529-6536, that is by reacting a compound of formula (X) with sodium amalgam and K2HP04 in a suitable solvent (such as an alcohol, for example methanol) at a suitable temperature (such as   0 C).   



   Alternatively a compound of formula (I), wherein R is hydroxy, can be prepared by the process outlined in Scheme II. Throughout Scheme II R3 and
R4 are, independently, unsubstituted   C16    alkyl, and X' and X" are, independently, a leaving group (such as halogen, for example chlorine).



   Thus, a compound of formula (I) wherein R is hydroxy can be prepared by decarboxylating a compound of formula (V), preferably by using a suitable source of acid such as an ion exchange resin (for example
Amberlite IR-120(H+)). A compound of formula (V) can be prepared by hydroysis of a compound of formula (VI), preferably by using a base (for example sodium hydroxide) in a suitable solvent. A compound of formula (VI) can be prepared by reacting a compound of formula (VII) with an acid (such as a strong mineral acid, for example hydrochloric acid) in a suitable solvent (such as an alcohol, for example ethanol). A compound of formula (VII) can be prepared by reacting a compound of formula (IX) with a compound of formula (VIII) in the presence of a suitable base (such as an alkali metal alkoxide, for example sodium ethoxide).



   A compound of formula (I), wherein R is other than OH but not a nitrogen atom which is included in a peptide residue, can be prepared from a compound of formula (I), wherein R is OH, using standard literature methods (such as B. Nieses and W. Steglich, Org. Synth. (1985)   63    183).



  They can also be prepared from a compound of formula   (II),    using standard methods, followed by deprotection of the resulting product.



   Salts of a compound of formula (I) can be prepared using standard methods.



   A compound of formula (I), wherein R is a nitrogen atom which is included in a peptide residue, can be made be reacting the peptide, which could have the carboxylic acid moiety suitably protected, with a compound  of formula (II)or a derivative thereof (such as the acid chloride) using standard literature conditions (such as those in G.W. Anderson, J.E.



  Zimmerman and F.M. Callahan, J. Amer. Chem. Soc. (1964)   86    1839). The resulting product can then be deprotected using literature conditions (for example the conditions given above or R. Andruszkiewicz, S. Milewski, T.



  Zieniawa and E. Borowski, J. Med. Chem. (1990)   33    132).



   In a further aspect the present invention provides a method for preparing a compound of formula (I) as hereinbefore described.



   The compounds of formula (I) show fungicidal activity against the class of pathogens known as the phycomycetes (equivalent to the oomycetes).



  These include species of Phytophthora, Plasmopara, Peronospora and
Pseudoperonospora. Examples of pathogens which the invention compounds are particularly useful for controlling are: Plasmopara viticola on vines; other downy mildews such as Bremia lactucae on lettuce;   Peronosoora    spp. on soybeans, tobacco, onions and other hosts;   Pseudoperonospora    humuli on hops and   Pseudoperonospora    cubensis on cucurbits; Phvtophthora infestans on potatoes and tomatoes and other   Phvtonhthora    spp. on vegetables, strawberries, avocado, pepper, ornamentals, tobacco, cocoa and other hosts; and   Pvthium    sp on rice, horticultural plants, vegetables and turf.



   It is preferred that all compositions, both solid and liquid formulations, comprise 0.0001 to 95%, more preferably 1 to 85%, for example 1 to 25% or 25 to 60%, of a compound of formula (I).



   When applied to the foliage of plants, the compounds of the invention are applied at rates of   O.1g    to   1OKg,    preferably   1g    to 8Kg, more preferably 109 to 4Kg, of active ingredient per hectare.



   When used as seed dressings, the compounds of the invention are used at rates of 0.00019 (for example 0.001g or 0.05g) to 109, preferably 0.0059 to 89, more preferably 0.005g to 49, of active ingredient per kilogram of seed.



   The compounds can be applied in a number of ways. For example, they can be applied, formulated or unformulated, directly to the foliage of a plant, to seeds or to other medium in which plants are growing or are to be planted, or they can be sprayed on, dusted on or applied as a cream or paste formulation, or they can be applied as a vapour or as slow release granules.



   The compositions of the present invention show exceptional activity  against the pathogen Plasmopara viticola (vine downy mildew). Therefore, in another aspect the present invention provides a method for combating the pathogen   Plasmorpara    viticola which comprises applying to vines or to their locus a composition as hereinbefore defined.



   Application can be to any part of the plant including the foliage, stems, branches or roots, or to soil surrounding the roots, or to the seed before it is planted, or to the soil generally or to hydroponic culture systems. The invention compounds may also be injected into plants or sprayed onto vegetation using electrodynamic spraying techniques or other low volume methods.



   The term "plant" as used herein includes seedlings, bushes and trees.



  Furthermore, the fungicidal method of the invention includes preventative, protectant, prophylactic, systemic and eradicant treatments.



   The compositions may be in the form of dustable powders or granules comprising the active ingredient and a solid diluent or carrier, for example, fillers such as kaolin, bentonite, kieselguhr, dolomite, calcium carbonate, talc, powdered magnesia, fullers earth, gypsum, diatomaceous earth and china clay. Such granules can be preformed granules suitable for application to the soil without further treatment. These granules can be made either by impregnating pellets of filler with the active ingredient or by pelleting a mixture of the active ingredient and powdered filler.



  Compositions for dressing seed may include an agent (for example, a mineral oil) for assisting the adhesion of the composition to the seed; alternatively the active ingredient can be formulated for seed dressing purposes using an organic solvent (for example,   li-methylpyrrol-idone,    propylene glycol or   N,N-dimethylformamide).    The compositions may also be in the form of wettable powders or water dispersible granules comprising wetting or dispersing agents to facilitate the dispersion in liquids. The powders and granules may also contain fillers and suspending agents.

 

   The compositions may be in the form of soluble powders or granules, or in the form of solutions in polar solvents.



   Soluble powders may be prepared by mixing the active ingredient with a water-soluble salt such as sodium bicarbonate, sodium carbonate, magnesium sulphate or a polysaccharide, and a wetting or dispersing agent to improve water dispersibility/solubility. The mixture may then be ground to a fine powder. Similar compositions may also be granulated to form water-soluble  granules. Solutions may   beyprepared    by dissolving the active ingredient in polar solvents such as ketones, alcohols and glycol ethers. These solutions may contain surface active agents to improve water dilution and prevent crystallisation in a spray tank.



   Emulsifiable concentrates or emulsions may be prepared by dissolving the active ingredient in an organic solvent optionally containing a wetting or emulsifying agent and then adding the mixture to water which may also contain a wetting or emulsifying agent. Suitable organic solvents are aromatic solvents such as alkylbenzenes and alkylnaphthalenes, ketones such as cyclohexanone and methylcyclohexanone, chlorinated hydrocarbons such as chlorobenzene and trichlorethane, and alcohols such as benzyl alcohol, furfuryl alcohol, butanol and glycol ethers.



   Suspension concentrates of largely insoluble solids may be prepared by ball or bead milling with a dispersing agent with a suspending agent included to stop the solid settling.



   Compositions to be used as sprays may be in the form of aerosols wherein the formulation is held in a container under pressure of a propellant, e.g. fluorotrichloromethane or dichlorodifluoromethane.



   The compounds of formula (I) can be mixed in the dry state with a pyrotechnic mixture to form a composition suitable for generating in enclosed spaces a smoke containing the compounds.



   Alternatively, the compounds may be used in micro-encapsulated form.



  They may also be formulated in biodegradable polymeric formulations to obtain a slow, controlled release of the active substance.



   By including suitable additives, for example additives for improving the uptake, distribution, adhesive power and resistance to rain on treated surfaces, the different compositions can be better adapted for various utilities. Other additives may be included to improve the biological efficacy of the various formulations. Such additives can be surface active materials to improve the wetting and retention on surfaces treated with the formulation and also the uptake and mobility of the active material, or additionally can include oil based spray additives, for example, certain mineral oil and natural plant oil (such as soya bean and rape seed oil) additives, or blends of them with other adjuvants.



   The compounds can be used as mixtures with fertilisers (e.g.



  nitrogen-, potassium- or phosphorus-containing fertilisers). Compositions  comprising only granules of fertiliser incorporating, for example coated with, a compound of formula (I) are preferred. Such granules suitably contain up to 25% by weight of the compound. The invention therefore also provides a fertiliser composition comprising a fertiliser and the compound of general formula (I) or a salt or metal complex thereof.



   Wettable powders, emulsifiable concentrates and suspension concentrates will normally contain surfactants, e.g. a wetting agent, dispersing agent, emulsifying agent or suspending agent. These agents can be cationic, anionic or non-ionic agents.



   Suitable cationic agents are quaternary ammonium compounds, for example, cetyltrimethylammonium bromide. Suitable anionic agents are soaps, salts of aliphatic monoesters of sulphuric acid (for example, sodium lauryl sulphate), and salts of sulphonated aromatic compounds (for example, sodium dodecylbenzenesulphonate, sodium, calcium or ammonium lignosulphonate, butylnaphthalene sulphonate, and a mixture of sodium diisopropyl- and triisopropylnaphthalene sulphonates).



   Suitable non-ionic agents are the condensation products of ethylene oxide with fatty alcohols such as oleyl or cetyl alcohol, or with alkyl phenols such as octyl- or nonylphenol and octylcresol. Other non-ionic agents are the partial esters derived from long chain fatty acids and hexitol anhydrides, the condensation products of the said partial esters with ethylene oxide, and the lecithins. Suitable suspending agents are hydrophilic colloids (for example, polyvinylpyrrolidone and sodium carboxymethylcellulose), and swelling clays such as bentonite or attapulgite.



   Compositions for use as aqueous dispersions or emulsions are generally supplied in the form of a concentrate containing a high proportion of the active ingredient, the concentrate being diluted with water before use.



  These concentrates should preferably be able to withstand storage for prolonged periods and after such storage be capable of dilution with water in order to form aqueous preparations which remain homogeneous for a sufficient time to enable them to be applied by conventional spray equipment. The concentrates may conveniently contain up to 95%, suitably 1-85%, for example 1-25% or 25-60%, by weight of the active ingredient.



  After dilution to form aqueous preparations, such preparations may contain varying amounts of the active ingredient depending upon the intended  purpose, but an aqueous preparation   containingeO.0001    to 10%, for example 0.005 to 10%, by weight of active ingredient may be used.



   The compositions of this invention may contain other compounds having biological activity, e.g. compounds having similar or complementary fungicidal activity or which possess plant growth regulating, herbicidal or insecticidal activity.



   An additional fungicidal compound may be present in the composition of the invention. By including another fungicide, the resulting composition can have a broader spectrum of activity or a greater level of intrinsic activity than the compound of formula (I) alone. Further the other fungicide can have a synergistic effect on the fungicidal activity of the compound of formula (I).

  Examples of fungicidal compounds which may be included in the composition of the invention are   (RS)-1-aminopropyl-    phosphonic acid,   (RS)-4-(4-chlorophenyl)-2-phenyl-2-(lH-1,2,4-triazol-1-yl-    methyl)butyronitrile,   (Z)-N-but-2-enyloxymethyl-Z-chloro-2',6'-diethylacet-    anilide, 1-(2-cyano-2-methoxyiminoacetyl)-3-ethyl urea, 4-(2,2-difluoro   -1,3-benzodioxol-4-yl)pyrrole-3-carbonitrile,    4-bromo-2-cyano-N,N-dimethyl -6-trifluoromethylbenzimidazole-1-sulphonamide, 5-ethyl-5,8-dihydro-8   -oxo(1,3)-dioxol-(4,5-g)quinoline-7-carboxylic    acid,    -D!-(3-chloro-2,6-    -xylyl)-2-methoxyacetamido]-g-butyrolactone,   li-(2-methoxy-5-pyridyl)-cyclo-    propane carboxamide, alanycarb, aldimorph, ampropylfos, anilazine, azaconazole,

   BAS 490F, benalaxyl, benomyl, biloxazol, binapacryl, bitertanol, blasticidin S, bromuconazole, bupirimate, butenachlor, buthiobate, captafol, captan, carbendazim, carbendazim chlorhydrate, carboxin, chinomethionate, chlorbenzthiazone, chloroneb, chlorothalonil, chlorozolinate, clozylacon, copper containing compounds such as copper oxychloride, copper oxyquinolate, copper sulphate, copper tallate, and
Bordeaux mixture, cycloheximide, cymoxanil, cyproconazole, cyprofuram, debacarb, di-2-pyridyl disulphide 1,1'-dioxide, dichlofluanid, dichlone, diclobutrazol, diclomezine, dicloran, didecyl dimethyl ammonium chloride, diethofencarb, difenoconazole,   Q,Q-di-iso-propyl-S-benzyl    thiophosphate, dimefluazole, dimetconazole, dimethomorph, dimethirimol, diniconazole, dinocap, dipyrithione, ditalimfos, dithianon, dodemorph, dodine, doguadine, edifenphos, epiconazole, 

   etaconazole, ethirimol, ethoxyquin, ethyl    (Z)-N-benzyl-N-([methyl(methyl-thioethylideneamino-oxyCarbonyl)amino]thio)-      -p-alaninate,    etridiazole, fenaminosulph, fenapanil, fenarimol,     fenconazole,    fenfuram, fenpiclonil, fenpropidin, fenpropimorph, fentin acetate, fentin hydroxide, ferbam, ferimzone, fluazinam, fludioxonil, fluoroimide, fluquinconazole, flusilazole, flutolanil, flutriafol, folpet, fuberidazole, furalaxyl, furconazole-cis, guazatine, hexaconazole, hydroxyisoxazole, hymexazole,   ICIA5504,    imazalil, imibenconazole, ipconazole, iprobenfos, iprodione, isopropanyl butyl carbamate, isoprothiolane, kasugamycin, mancozeb, maneb, mepanipyrim, mepronil, metalaxyl, metconazole, methfuroxam, metiram, metiram-zinc, metsulfovax,

   myclobutanil,   NTN0301,    neoasozin, nickel dimethyldithiocarbamate, nitrothal-isopropyl, nuarimol, ofurace, organomercury compounds1 oxadixyl, oxolinic acid, oxycarboxin, pefurazoate, penconazole, pencycuron, phenazin oxide, phosetyl-Al, phosphorus acids, phthalide, polyoxin D, polyram, probenazole, prochloraz, procymidone, propamocarb, propamocarb hydrochloride, propiconazole, propineb, propionic acid, prothiocarb,   pyracarbol id,    pyrazophos, pyrifenox, pyrimethanil, pyroquilon, pyroxyfur, pyrrolnitrin, quaternary ammonium compounds, quinconazole, quinomethionate, quintozene, rabenazole, sodium pentachlorophenate, streptomycin, sulphur, tebuconazole, techlofthalam, tecnazene, tetraconazole, thiabendazole, thicyofen, thifluzamide, 2-(thiocyanomethylthio)benzothiazole, thiophanate-methyl, thiram, timibenconazole, tolclofos-methyl,

   tolylfluanid, triacetate salt of 1,1'-iminodi(octamethylene)diguanidine, triadimefon, triadimenol, triazbutyl, triazoxide, tricyclazole, tridemorph, triforine, triflumizole, triticonazole, validamycin A, vapam, vinclozolin,
XRD-563, zineb and ziram. The compounds of formula (I) can be mixed with soil, peat or other rooting media for the protection of plants against seed-borne, soil-borne or foliar fungal diseases.



   Examples 1 to 6 demonstrate the preparation of compounds of formula (I) while Example 7 illustrates the biological testing of compounds of formula (I).



   Abbreviations used in reporting the NMR data are as follows:
 s = singlet dd = double doublet
 d = doublet ddd = doublet of double doublets
 t = triplet ABq = AB quartet
 m = multiplet dt = double triplet
 q = quartet br = broad  
 "DISPERSOL T" is a Trade Mark or Trade Name.



   EXAMPLE 1
 Preparation of (2S)-4-methylene-2-pyrrolidinecarboxylic acid, alternatively named 4-methylene-(L)-proline (Compound No. 1 of Table I).



  Step 1
 Preparation of   (2S,4B)-N-tert-butoxycarbonyl-4-hydroxy-2-pyrrolidine-    carboxylic acid.



   2-(tert-Butoxycarbonyloxyimino)-2-phenylacetonitrile (49.259, 0.200 mole) was added to a rapidly stirred solution of   (2S,4B)-4-hydroxy-2-    pyrrolidinecarboxylic acid (26.23g, 0.200 mole) in a mixture of water (200ml), methanol   (300ml),    dioxane (lOOml), and triethylamine (42ml,   0.30mol).    After   2    hours the solvent was evaporated under reduced pressure to provide a gum, which was dissolved in water   (600ml).    The solution was washed with diethyl ether, acidified to pH 3 by the addition of aqueous citric acid, saturated with sodium chloride, and extracted with ethyl acetate.

  The combined extracts were dried and evaporated to provide a gum, which was crystallised from diethyl ether to yield the title compound as a white solid (32.0g, 69%). mp   122"C.    IR (nujol mull) 3364, 2620, 1734, 1660   cm 1;    1H NMR   (CD3SOCD3):8    4.28(1H,m), 4.18(1H,t), 3.42(1H,dd), 3.28(1H,ddd), 2.10(1H,m), 1.95(1H,m), 1.39(9H,s) ppm.



  Step 2
 Preparation of   (2S)-N-tert-butoxycarbonyl-4-oxo-2-pyrrolidine-    carboxylic acid.



   A solution of   (2S,4B)-N-tert-butoxycarbonyl-4-hydroxy-2-pyrrolidine-    carboxylic acid (26.0g, 0.113 mole) in pyridine (lOml) and dichloromethane   (80ml)    was added to a solution of chromium trioxide (67.2g, 0.672 mole) in pyridine (108ml) and dichloromethane (1400ml). After stirring for 5 hours, the solution was decanted and the residue washed with acetone. The combined organic washings were evaporated to leave a gum, which was dissolved in brine and ethyl acetate. The aqueous phase was adjusted to pH 3 by the addition of aqueous hydrogen chloride, both phases were filtered and then separated. The aqueous phase was extracted with ethyl acetate.



  The combined organic extracts were dried, treated with charcoal, filtered and evaporated to provide a gum. Crystallisation from dichloromthane-ether yielded the title compound as a solid (3.91g). Further product   (8.0g)    was recovered by evaporation of the mother liquors. mp   1300C    (dec.); IR   (CH2Cl2) 1766, 1700   cm 1;    1H NMR   (CD3SOCD3):s    4.52(1H,d), 3.68(2H,ABq), 3.01(1H,dd), 2.39(1H,d), 1.35(9H,s) ppm.



  Step3
 Preparation of   (2)-li-tert-butoxycarbonyl-4-methylene-2-pyrrolidine-    carboxylic acid.



   Methyltriphenylphosphonium bromide (49.5g, 0.139 mole) was added to a stirred suspension of hexane-washed sodium hydride (60% in oil, 5.5g, 0.14 mole) in tetrahydrofuran (350ml). The mixture was heated at 500C for   5    hours, then a solution of (2S)-N-tetr-butoxycarbonyl-4-oxo-2-pyrrolidine- carboxylic acid (7.99, 0.03 mole) in tetrahydrofuran (70ml) was added over 30 minutes. The mixture was stirred at 500C for 17 hours, then cooled and poured into aqueous sodium bicarbonate. The solution was washed with diethyl ether, acidified to pH 3 with aqueous citric acid, and extracted with ethyl acetate. The extract was dried and evaporated to provide an oil which was purified by column chromatography (eluant: ethyl acetate:acetic acid, 99:1) to yield the title compound as a gum (2.1g).



  IR (liquid) 2900, 1750, 1704, 1665   cm 1;    1H NMR   (CDCl3):8    5.03(2H,s), 4.45(1H,m), 4.03(2H,m), 2.90(2H,m), 1.45(9H,d) ppm.



     Step 4   
 Preparation of (2S)-4-methylene-2-pyrrolidinecarboxylic acid.



   A solution of   (2X)-N-tert-butoxycarbonyl-4-methylene-2-pyrrolidine-    carboxylic acid (1.77g, 7.41 mmol) in 85% aqueous formic acid (55ml) was stirred for 5 hours, then the solvent was evaporated to leave a gum.



  Isopropanol was added, and the resulting solid filtered and dried to yield the title compound (782mg). mp 229 C.   [&alpha;]D25    = -50.4 C (c=0.01 in H2O); ÚH
NMR   (D20):5    5.19(2H,dt), 4.26(1H,t),   3.98(2H,ABq),    2.90(2H,ABx) ppm.

 

   EXAMPLE 2
 Preparation of methyl (2S)-4-methylene-2-pyrrolidinecarboxylate, hydrochloride salt (Compound No.10 in Table I).



   Acetyl chloride (0.64 ml, 8.96 mmol) was added dropwise to a solution of (2S)-N-tetr-butoxycarbonyl-4-methylene-2-pyrrolidinecarboxylic acid (370mg, 1.63 mmol) in methanol (10 ml). The solution was kept at   0OC    for 30 minutes, then allowed to warm to ambient temperature over 1 hour. The solvent was evaporated to leave a solid which was crystallised from methanol:ether to yield the title compound (161 mg). mp 150-152 C. 1H NMR (CD30D):   b    5.25(2H,m), 4.61(1H,t), 4.01(2H,q), 3.85(3H,s), 3.12(1H,dd),  2.85(1H,dd) ppm.



   EXAMPLE 3
 Preparation of benzyl (2S)-4-methylene-2-pyrrolidinecarboxylate, hydrochloride salt (Compound No.71 in Table I).



     Steps   
 Preparation of benzyl (2S)-N-tert-butoxycarbonyl-4-methylene-2-   pyrrol idinecarboxylate.   



   1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (0.929 g, 4.85 mmol) was added in portions to a solution of   (2X)-      li-tert-butoxycarbonyl-4-methylene-2-pyrrolidinecarboxylic    acid (0.50 g, 2.2 mmol), 4-dimethylaminopyridine (catalytic) and benzyl alcohol (0.476 g, 4.4 mmol) in dichloromethane (30 ml) and the mixture stirred under nitrogen for 2 hours. Water was added and the mixture extracted with dichloromethane.



  The extract was dried and evaporated to leave an oil, which was purified by column chromatography (eluant: ethyl acetate:hexane:acetic acid, 1:2:0.01) to yield the title compound (0.431 g). 1H NMR (CDCl3): 8   7.34(5H,s),    5.17(2H,m), 4.99(2H,m), 4.50(1H,ddd), 4.07(2H,d), 2.96(1H,m),   2.61(1H,br    s), 1.47 and 1.35(9H,s) ppm.



  Step 2
 Preparation of benzyl (2S)-4-methylene-2-pyrrolidinecarboxylate, hydrochloride salt.



   A solution of benzyl (2S)-N-tert-butoxycarbonyl-4-methylene-2- pyrrolidinecarboxylate (297 mg, 0.94 mmol) in trifluoroacetic acid (2 ml) was stirred under nitrogen at   0 C    for 2 hours, then allowed to warm to ambient temperature and the solvent evaporated to yield the title compound as an oil (255 mg). 1H NMR (CDCl3): 8   7.35(5H,m),    5.22(2H,ABq), 5.18(2H,m),   4.58(1H,dd),    4.01(2H,m), 3.10(1H,dd), 2.84(1H,dd) ppm.



   EXAMPLE 4
 Preparation of   (2X)-4-methylene-2-pyrrolidine-N-methylcarboxamide,    trifluoroacetate salt (Compound No.2 of Table II).



     Steps   
 Preparation of   li-hydroxysuccinimidyl      (2) -li-tert-butoxycarbonyl -4-    -methylene-2-pyrrolidinecarboxylate.



   Dicyclohexyl carbodiimide (2.04 g, 9.88 mmol) was added to a stirred solution of (2S)-N-tert-butoxycarbonyl-4-methylene-2-pyrrolidinecarboxylic acid (2.04 g, 8.98 mmol) and   li-hydroxysuccinimide    (1.03 g, 8.98 mmol) in  ethyl acetate (20 ml). The mixture was stirred at 0 C under nitrogen for 2.



  hours and then allowed to stand at this temperature for 18 hours. The mixture was then filtered and the filtrate evaporated to provide an oil that was purified by column chromatography (eluant: ethyl acetate:hexane, 1:1) to yield a white solid. This was crystallised from ethyl acetate:hexane to yield the title compound (2.24 g). 1H NMR (CDCl3):   8      5.09(2H,m),    4.71(1H,dd), 4.12(2H,m), 3.18(1H,dd), 2.93(1H,br d), 2.86(4H,s),   1.49(9H,s)    ppm.



     Step 2   
 Preparation of   (2S)-N-tert-butoxycarbonyl-4-methylene-2-pyrrolidine-      li-methyl carboxami de.   



     Methyl amine    was bubbled through a solution of triethylamine (374 mg, 6.17 mmol) in methanol (5 ml) at 0 C for 30 minutes. A solution of   li-hydroxysuccinimidyl    (2i -tert-butoxycarbonyl-4-methylene-2-pyrrolidinecarboxylate (1 g, 3.08 mmol) in methanol (5 ml) was added dropwise and the mixture stirred under nitrogen for 30 minutes. Water was added and the mixture extracted with ethyl acetate. The extract was dried and evaporated to leave an oil which was purified by column chromatography (eluant: ethyl acetate:hexane, 1:1) to yield the title compound as an oil (0.74 g). 1H
NMR (CDCl3): 8 5.00(2H,m), 4.42(1H,br s), 4.05(2H,q), 2.86(2H,m), 2.79(3H,d), 1.47(9H,s) ppm.



  Step 3
 Preparation of (2S)-4-methylene-2-pyrrolidine-N-methylcarboxamide, trifluoroacetate salt.



   A solution of   (2S)-N-tert-butoxycarbonyl-4-methylene-2-pyrrolidine-      li-methylcarboxamide    (1.2 g, 5 mmol) in trifluoroacetic acid (3 ml) was allowed to stand for 18 hours, then the solvent was evaporated to yield the title compound as an oil (0.68   g).    1H NMR   (CD3OD):      8    5.21(2H,m), 4.37(1H,t), 3.98(2H,q), 3.23(1H,dd), 2.90(3H,s), 2.80(1H,m) ppm.



   EXAMPLE 5
 Preparation of   ((S)-4-methyleneprolyl)-(S)-alanyl-(S)-alanine,    trifluoroacetate salt (Compound No.24 in Table III).



  Step 1
 Preparation of ((S)-N-tert-butoxycarbonyl-4-methyleneprolyl)-(S)alanyl-(S)-alanine.  



   A solution of   N-hydroxysuccinimidyl      (2S)-N-tert-butoxycarbonyl-4-    methylene-2-pyrrolidinecarboxylate (500 mg, 1.54 mmol) in methanol (10 ml) was added dropwise to a solution of   (S)-alanyl-(X)-alanine    (247 mg, 1.54 mmol) and triethylamine (312 mg, 3.09 mmol) in methanol (10 ml) and the mixture stirred under nitrogen at   5"C    for 30 minutes, then at ambient temperature for 6 hours. The solvent was evaporated to leave a gum which was purified by column chromatography (eluant: ethyl acetate:hexane:acetic acid, 1:2:0.01) to yield the product (246 mg). 1H NMR (CD3SOCD3): 8   8.15(2H,m),    4.96(2H,d), 4.33(2H,m), 4.20(1H,m), 3.96(2H,br s), 3.39(1H,br s), 2.92(1H,m), 1.37(9H,s), 1.30(3H,d), 1.24(3H,d) ppm.



  Step2
 Preparation of   ((S)-4-methyleneprolyl)-(S)-alanyl-(S)-alanine,    trifluoroacetate salt.



   A solution of   (X)-N-tert-butoxycarbonyl-4-methyleneprolyl)-(S)-alanyl-    (S)-alanine (100 mg, 0.26 mmol) in trifluoroacetic acid (2 ml) was stirred for 2 hours, then the solvent was evaporated to yield the title compound (68 mg). 1H NMR   (CD3OD):    8 5.28(2H,br s),   4.42(3H,m),      4.01(2H,q),    3.15(1H,dd), 2.80(1H,dd), 1.40(6H,d) ppm.



   EXAMPLE 6
 The compounds of formula (I) were tested against the diseases   Plasmopora    viticola on vine and   Phytophthora    infestans   lvcooersici    on tomato. The technique employed was as follows.



   The plants were grown in John Innes Potting Compost (No. 1 or 2) in 4cm diameter minipots. The test compounds were formulated either by bead milling with aqueous "DISPERSOL T" or as a solution in acetone or acetone/ethanol which was diluted to the required concentration immediately before use. The formulations (100 ppm active ingredient) were applied to the roots of the plants in the soil. The root drenches were applied to a final concentration equivalent to approximately 40 ppm a.i. in dry soil.

 

   For most of the tests the compounds were applied to the soil (roots) one or two days before the plant was inoculated with the disease. The pathogens were applied by spray as spore suspensions onto the leaves of test plants. After inoculation, the plants were put into an appropriate environment to allow infection to proceed and then incubated until the disease was ready for assessment. The period between inoculation and assessment varied from four to seven days according to the disease and  environment.



   The disease control was assessed by visual assessment of the percentage leaf area covered by actively sporulating disease. Assessments were performed on a single leaf of each of the two replicate plants, and the mean value of these two recordings was calculated for each treatment.



  The mean value for each treatment was then expressed as a percentage of the level of disease present on the untreated control plants. This calculated value is referred to as a POCO (Percentage of Control) value. An example of a typical calculation is as follows:
 Mean disease level on untreated Control = 90
 Mean disease level on treatment A = 30
 POCO Mean disease level on treatment A
 for treatment A =   ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯    x 100
 Mean disease level on untreated Control
 30
 =   ¯    x 100 = 33.3
 90
 Thus a POCO value of 0 indicates complete disease control.

 

   The results are shown in Table V.



   TABLE V
Compound No.   Pv    syst   Pil    syst
 (Table No.)
 1(I)   O    7
 2(I) 0 64
 3(I) 0
   lO(I)      O    15
 13(I) 0 4
 22(I) 0  
Compound No. Pv syst Pil syst (Table No.) 71(I) 0 20
 1(II) 0
 2(11) 75 100 11(II) 78 24(111) 0 48
 Pv = Plasmopara viticol
   fil    = Phvtophthora infestans lycopersici
 syst = root drench  
CHEMICAL FORMULA (IN DESCRIPTION)
EMI26.1     
  
CHEMICAL FORMULA (IN DESCRIPTION)
Scheme I
EMI27.1     
  
CHEMICAL FORMULA (IN DESCRIPTION)
Scheme II
EMI28.1

Claims

CLAIMS 1. A fungicidal composition comprising a fungicidally effective amount of a compound of formula (I): EMI29.1 wherein R is OH, optionally substituted alkoxy, optionally substituted phenoxy, optionally substituted phenylalkoxy, alkenyloxy, NR5R6 (wherein R5 and R6 are, independently, hydrogen, optionally substituted alkyl, optionally substituted phenyl or optionally substituted phenylalkyl) or a nitrogen atom which is included in a peptide residue; or a salt thereof, and a fungicidally acceptable carrier or diluent therefor.

2. A fungicidal composition as claimed in claim 1 wherein R is OH, optionally substituted alkoxy, optionally substituted phenoxy, optionally substituted phenylalkoxy, or alkenyloxy.

3. A fungicidal composition as claimed in claim 1 or 2 wherein R is OH or unsubstituted C16 alkoxy.

4. A fungicidal composition as claimed in claim 1, 2 or 3 wherein the compound of formula (I) is the (L) isomer.

5. A fungicidal composition as claimed in claim 1, 2, 3 or 4 wherein R is OH, methoxy or ethoxy, the compound of formula (I) being the (L) isomer.

6. A fungicidal composition as claimed in claim 1, 2, 3, 4 or 5 wherein the compound of formula (I) is in the form of a hydrochloride salt.

7. A method of combating fungi which comprises applying to plants, to seeds of plants or to the locus of the plants or seeds a compound of formula (I) or a composition according to claim 1.

8. A compound of formula (I): EMI30.1 wherein R is OH, optionally substituted alkoxy, optionally substituted phenoxy, optionally substituted phenylalkoxy, alkenyloxy, NR5R6 (wherein R5 and R6 are, independently, hydrogen, optionally substituted alkyl, optionally substituted phenyl or optionally substituted phenylalkyl) or a nitrogen atom which is included in a peptide residue; and salts thereof; provided that when R is OH then the compound is in the form of a salt, but not a hydrochloride salt, and that when R is methoxy and the compound is the L isomer then the compound is in the form of a salt, but not a hydrochloride salt.

9. A compound of formula (I) as claimed in claim 8 wherein R is unsubstituted C26 alkoxy, or a salt thereof.

10. A salt of a compound of formula (I) as claimed in claim 8 wherein R is OH or methoxy; provided that the salt is not a hydrochloride salt.

11. A salt of a compound of formula (I) as claimed in claim 8 wherein R is OH, the compound of formula (I) being the (L) isomer.

12. A salt of a compound of formula (I) as claimed in claim 8 wherein R is methoxy, the compound of formula (I) being the (L) isomer; provided that the salt is not a hydrochloride salt.

13. A process for preparing a compcund as claimed in claim 8, the process comprising either: a) deprotecting a compound of formula (II): EMI31.1 b) decarboxylating a compound of formula (V): EMI31.2 using a suitable source of acid; or c) reacting a compound of formula (X): EMI31.3 with sodium amalgam and K2HPO4 in a suitable solvent.