1,3-Oxathia-, 1,3-Dioxa- and 1,3-Dithiolanes from α,β-Unsaturated Aldehydes

The protection of carbonyl compounds plays an important role during multistep syntheses in organic, medicinal, carbohydrate, and drug design chemistry. Among various carbonyl protecting groups, 1,3-oxathiolane, 1,3-dioxolane, 1,3- dithiolane are important because of their stability and the preparation ease. This review summarizes and highlights methods for the synthesis of S,O-, O,O- and S,S-cyclic acetals based on transformations of α,β-enals.