Reaction of Dess-Martin periodinane with 2-(alkylselenyl)pyridines. Dehydration of primary alcohols under extraordinarily mild conditions

Dess-Martin periodinane oxidizes very rapidly 2-pyridylseleno derivatives RR′CHCH2SePy in CHCl3 or CH2Cl2 and more chemoselectively than mCPBA. Tetravalent selenanes, RR′CHCH2Se(OAc)2Py, seem to be formed. Treatment of these intermediates with aqueous NaHCO3 gives rise to irreversible hydrolysis and elimination to terminal alkenes. As the OH/SePy exchange can be performed in minutes, the overall process is an exceptionally efficient procedure for the dehydration of primary alcohols.