FIELD: organic chemistry, pesticides. SUBSTANCE: invention relates to method of synthesis of pesticide fluoroolefin compound of the general formula (I): 
where R means hydrogen atom or C1-C4-alkyl; R1 means C1-C4-alkyl, C1-C4-halogenalkyl or cyclopropyl; or R and R1 taken in common with carbon atom to which they are bound form cyclopropyl group; Ar means phenyl optionally substituted with one-five groups taken independently among halogen atoms, C1-C4-alkyl groups, C1-C4-halogenalkyl groups, C1-C4-alkoxy-groups or C1-C4-halogenalkoxy-groups, or 1- or 2-naphthyl optionally substituted with one-three groups taken independently among halogen atoms, C1-C4-alkyl groups, C1-C4-halogenalkyl groups, C1-C4-alkoxy-groups or C1-C4-halogenalkoxy-groups; Ar1 means phenoxyphenyl optionally substituted with one-five groups taken independently among halogen atoms, C1-C4-alkyl groups, C1-C4-halogenalkyl groups, C1-C4-alkoxy- -groups or C1-C4-halogenalkoxy-groups; biphenyl, benzylphenyl or benzylphenyl optionally substituted with one-five groups taken independently among halogen atoms, C1-C4-alkyl groups, C1-C4-halogen-alkyl groups, C1-C4-alkoxy-groups or C1-C4-halogenalkoxy-groups. Configuration of groups ArCRR1- and -CH2Ar1 at double bond is reciprocally trans-configuration mainly. Method involves fluorination of 4-aryl-3- oxo-2-(substituted benzyl)-butanoate of the formula (II): 
where R2 means C1-C6-alkyl and values of other radicals are given above in the presence of the first base to yield 4-aryl-2-fluoro-3-oxo-2-(substituted benzyl)-butanoate of the formula (III): 
. The latter is reduced to yield 4-aryl-2-fluoro-3-hydroxy-2-(substituted benzyl)-butanoate of the formula (IV): 
. Configuration of groups ArCR-R1-CH(OH) and -CF(CO2R2)CH2Ar1 bound to the bond designated as "a" presents (R,S) and (S, R) or their racemate mainly. Compound is saponified to yield 4-aryl-2-fluoro-3- hydroxy-2-(substituted benzyl)-butanoic acid of the structural formula (V) 
and configuration of groups ArCR-R1-CH(OH) and -CF(CO2H)CH2Ar1, bound to the bond designated as "a" presents (R,S) and (S, R) or their racemate mainly. Then interaction of compound of the formula (V) with sulfohalide and the second base is performed. The first base is taken among the group comprising of alkaline, alkaline-earth metal hydroxide, alkaline or alkaline-earth metal C1-C6-alkoxide, thallium (I) C1-C6-alkoxide, thallium (I) hydroxide, alkaline metal hydride, alkylmethyl group and aryllithium. The second base presents tertiary amine taken among the group comprising of tris-(C1-C4-alkyl)-amine, pyridine and substituted pyridine. Invention relates also to novel intermediate compounds of structural formulas: (II), (III), (IV) and (V). Said method does not require Grignard reagents, compounds of alkaline metals and catalysts based on transient metals. EFFECT: improved method of synthesis, enhanced effectiveness and economy. 15 cl, 7 ex
