Stereochemistry of reduction of (–)-thujone and (—)-isothujone

Abstract

The title compounds have been converted into mixtures of isomeric thujols by seven aluminium and boron hydrides of differing stereoselectivity, and also by two aluminium alkoxides in Meerwein–Ponndorf–Verley reactions. The products can be rationalised on the basis of recently proposed configurations for thujones and thujols. Convenient methods are described for the preparation of thujone, isothujone, thujol, neothujol, neoisothujol, and isothujol. A claim to prepare both thujones and thujols by base-promoted condensation of acetone could be substantiated.