Studies on enethiols VII : Thio-claisen rearrangements of some enethiolderivatives

Abstract

Enethiols, derived from ethyl acetoacetate and ethyl benzoylacetate have been alkylated with allyl- crotyl- and propargyl bromides to give ethyl 3-alkylthio-crotonates (E- and Z-forms) and ethyl 3-alkylthio-cinnamates (Z-form). The Z-forms of the alkylated crotonates are smoothly converted to the corresponding E-forms by heat or irradiation. The sulphides undergo different rearrangement reactions in solvents like acetic anhydride, pyridine, triethylamine and quinoline leading to a variety of products including derivatives of thiophene and 2 H-thiopyran.