Trans-3-3-dimethyl-2-r-cyclopropane-1-carboxylic

摘要

Compounds of formula (I): (where R' = -CH = ; R2 and R3 = alkyl(C1-6) or R2 + R3 form an alkylene chain (C4-6) are prepared by reacting (II) in an organic solvent in the presence of a strong base with a phosphonium salt (III) to give racemic-, 1R, 2R- or 1S, 2S trans 3,3-dimethyl 2-R'-cyclopropane 1-carboxylic acid or its alkyl esters. Alkaline hydrolysis gives (I): hydrolysis right arrow alkali (R1 = H or 1-4C alkyl)