A variety of carbonyl compounds can be easily and rapidly converted to the corresponding 1,3-oxathiolanes in the presence of a catalytic amount of scandium(III) triflate [Sc(OTf)3] in CH2Cl2. After completion of the reaction, the catalyst can straightforwardly be recovered using standard methods. Moreover, by employing this protocol, chemoselective oxathioacetalization of aldehydes in the presence of ketones can be achieved.
heterocycles - protecting groups - acetals - - scandium - aldehydes - ketones - catalysis