Chiral α-sulphinyl hydrazones as effective reagents for stereoselective aldol-type condensation
Abstract
The stereoselective aldol-type synthesis of optically active β-hydroxy hydrazones and β-hydroxy ketones mediated by chiral α-sulphinyl hydrazones is described. In some cases a good degree of enantioselectivity (up to 88%) is achieved. The factors affecting the stereochemical outcome of the process, i.e. the nature and stoicheiometry of the base and the structures and steric requirements of the α-sulphinyl hydrazones are discussed.