Studies on montmorillonite K10-microwave assisted isomerisation of Baylis–Hillman adduct. Synthesis of E-trisubstituted alkenes and synthetic application to lignan core structures by vinyl radical cyclization

Abstract

The isomerisation of acetates from the Baylis–Hillman adducts with Mont.K10 clay-microwave combination furnished E-trisubstituted alkenes in high yield. The simple Baylis–Hillman adducts with trimethyl orthoformate and unsaturated alcohols under clay catalytic condition gave densely functionalised-isomerized products under solvent free condition. Application of the propargyl derivatives thus obtained from the isomerisation of the Baylis–Hillman adducts with propargyl alcohol has been demonstrated in the synthesis of lignan core structures by tri- n-butyltin hydride mediated vinyl radical cyclization.