Annulation by sequential double Michael reaction; synthesis of decalones and its application to the syntheses of ε-cadinene, khusitone and khusilal

Abstract

Reaction of the kinetic enolates or the trimethylsilyl enol ethers of 1-acetylcyclohexenes with α,β-unsaturated carbonyl compounds affords 4-substituted 1 -decalone derivatives under basic or Lewis acidic conditions. The reaction with acrylates of chiral alcohols has achieved 70% diastereoselection. Application of these reactions has enabled syntheses of ε-cadinene, khusitone and khusilal to be accomplished.