Synthesis and stereochemical features of 2-oxo-3-cyano-1,2-thiaphosphorinanes

The intramolecular Pishchimuka rearrangement of 3-halopropyl-substituted thiophosphorylacetonitriles results in the corresponding 2-oxo-3-cyano-1,2-thiaphosphorinanes as a statistical mixture of two diastereomers, which transforms to an individual diastereomer with time; in benzene solution, the latter turns again into an equilibrium mixture of diastereomers.