Regio- and diastereo-selectivity in 1,3-dipolar cycloadditions of nitrile oxides to 4-substituted cyclopent-2-enones

Abstract

The behaviour of 4-hydroxy-4-methylcyclopent-2-enone and related 4-substituted cyclopent-2-enones towards 1,3-dipolar cycloaddition with nitrile oxides is studied. The reactions are always completely regioselective while the diastereofacial selectivity depends on the nature of the substituents. Remarkably, the reaction of 4-acetoxycyclopent-2-enone shows complete regio- and diastereo-facial selectivity.