Structure proof and synthesis of kotalanol and de-O-sulfonated kotalanol, glycosidase inhibitors from an herbal remedy for the treatment of type-2 diabetes

The exact stereochemical structures of kotalanol and de-O-sulfonated-kotalanol, which are used for the treatment of type-2 diabetes, are described by synthesis and comparison of their physical data to those of the corresponding natural compounds. The synthesis of kotalanol is achieved by coupling p-methoxybenzyl (PMP)-protected 4-thiol-D-arabinitol with a cyclic sulfate that is prepared from the naturally occurring D-perseitol.