METHOD OF PREPARING 2,2-DIMETHYL-3-[(Z)-1- PROPENYL)CYCLOPROPANE CARBOXYLIC ACID ESTERS AND INTERMEDIATE COMPOUNDS Russian patent published in 1999 - IPC

FIELD: organic chemistry. SUBSTANCE: present convention describes novel method of preparing cyclopropane carboxylic acid esters of formula I: wherein R is ester residue cleavable in neutral or acid medium and is C_1-18 alkyl optionally substituted by halogen or benzyl radical optionally substituted by one or more halogen atoms at apexes of aromatic ring, or radical of formula (a), (b) and (d) wherein R² is H or methyl; R³ is aryl; R⁴ is or CN or H; R⁵ is fluorine, bromine or hydrogen; R⁶, R⁷, R⁸, R⁶ are hydrogen or methyl; S/I denotes tetrahydrocycle. Method comprises treating ester of formula II: with about two equivalents of halogenating agent followed by treatment of compound III: obtained as mixture of isomers with main agent in the presence of compound R¹OH in corresponding cosolvent medium. Method is highly selective, since it leads to preparation of compounds of formula I with configuration (Z), that is, to biologically active form of said compounds. EFFECT: more efficient preparation method. 13 cl, 22 ex