A highly efficient and catalytic synthetic protocol for oxathioacetalization of carbonyl compounds

A variety of aldehydes and ketones can be converted easily to the corresponding 1,3-oxathiolane derivatives, on treating with 2-mercaptoethanol using a catalytic amount of bromodimethylsulfonium bromide as pre-catalyst at room temperature under solvent-free conditions. Some of the major privileges are: mild reaction conditions, high yields, no aqueous work-up and no chromatographic separation; which is highly economic and compatible in the presence of other protecting groups. Furthermore, no brominations occur either at the double bond or α to the keto position and even in the aromatic ring.