Stereochemistry of Diels–Alder reactions of allenic sulphones; transfer of asymmetry from allenic to norbornene systems
Abstract
Diels–Alder reactions of chiral allenic sulphones afford as main products the diastereoisomers derived by attack of the diene from the less hindered side of the double bond α to the sulphonyl group; starting from menthyl sulphinate, asymmetry is transmitted to the allenic sulphorie, and in turn to the Diels–Alder adduct, with a high degree of retention of chirality.