Electron-deficient cyclopropane derivatives 1 in anhydrous THF reacted with 2-mercaptoben- zothiazole (2) in a sealed tube to give the products 3 and 4 with high yield and stereoselectivity. The structures of 3 and 4 were identified as (R)-β-substituted-(R)-γ-(2-mercaptoben-zothiazolyl)-γ-p-substituted- phenylbutyric acid or (S)-β-substituted-(S)-γ-(2-mercaptobenzothiazolyl)-γ-p-substituted-phenylbutyric acid and trans-β-substituted-γ-p-substituted-phenyl-but-3-enic acid by means of MS, IR, ¹H NMR, ¹³C NMR, 2D-NOESY spectra and elemental analysis. The mechanism for the formation of products was also proposed.

Key words: electron-deficient cyclopropane derivative, polysubsti-tuted-but-3-enic acid, butyric acid derivative