α-Thioalkylation of Zinc Dienolates as an Entry to 4-Substituted 1-tert-Butoxy-7a-methylhexahydroindenes

Abstract

Hexahydroindenes 10 are readily available in 3 steps with an overall yield of 41 – 45 % starting from the Hajos Wiechert ketone 1. Alkylation of the α,β-unsaturated ketone 1 at C-4 has been achieved by thioalkylation of the corresponding zinc dienolate 2 with α-chlorosulfides of type 3. Subsequent in situ reduction and desulfurization of the β-(phenylthio) ketones 4 leads directly to the 4-substituted hexahydroindene-5-ols 6 which can be deoxygenated via their mesylates to the hexahydroindenes 10.