Abstract
The synthetic utility of ketene dithioacetals is reported in a formal way. The title compounds are used as precursors for the synthesis of many heterocyclic rings. The reactions of the title compounds are subdivided into groups that cover reactions yielding monoheterocycles e.g., thiophenes, imidazolidines, pyrimidines, pyridines, pyrazoles and even fused heterocyclic e.g., pyrroloimidazoles, pyrazolopyridines and imidazopyridines.