Regio- and stereoselective ring-opening of epoxides using organic dithiophosphorus acids as nucleophiles

A practical method for the synthesis of β-hydroxymercaptans has been successfully developed through the ring-opening of epoxides with organic dithiophosphorus acids 1. Highly regio- and stereoselective products, β-hydroxyalkyl dithiophosphates, which were transformed to the corresponding synthetically valuable β-hydroxymercaptans by further reduction, were obtained under mild reaction conditions without any catalyst or promoter. Highly enantioselective ring-opening reaction of cyclohexene epoxide with 1 was realized in the presence of a chiral (salen)Ti(IV) complex.