CONVENIENT SYNTHESES OF CHIRAL CYCLIC SULFINATES (SULTINES) FROM UNSATURATED ALCOHOLS

The reaction of unsaturated alcohols with N-sulfinyl-p-toluenesulfonamide (TsNSO) is shown to lead stereoselectively to chiral cyclic or bicyclic sulfinates (sultines). The reactions occur at ambient temperatures and afford a general route to delta- and epsilon-sultines which are notable for their crystallinity and thermal stability. These studies confirm the preservation of stereochemical integrity of the carbon atom alpha to the oxygen atom in the sultine ring. Some unsaturated aldehydes furnish sultines via a tandem oxo-ene cyclization and subsequent ring closure to the sultine. In some reactions, N-toluenesulfonamide derivatives of sultines (compounds of type 11) were isolated, and since those were converted into the sultines by the action of BF3-OEt(2), such sulfonamides are considered to be intermediates in the reaction pathway.