Arylbis(arylthio)sulfonium Salts as Reagents for the Synthesis of 2-Deoxy-β-glycosides

Article abstract of DOI:10.1021/jo00033a033

The title sulfonium salts undergo electrophilic addition to glycals in the presence of alcohols to form principally β-glycosides.A substituent effect study has shown that the reagent with a p-tolylthio group is the most face-selective.By variation of the alcohol nucleophile, it has been shown that face selectivity is also dependent on the structure of the nucleophile.One instance of double diastereodifferentiation was uncovered when the racemic alcohol 23.5 was used in a reaction with tribenzyl glucal 22.1.The effect of glycal substitution on the face selectivity has led to the postulation of a heretofore unrecognized and still unexplained stereoelectronic effect.