Ammonolysis of 1,6-anhydro-2,4-di- O-tosyl- β- d-glucopyranose and 1,6:3,4-dianhydro-2- O-tosyl-β- d-galactopyranose: preparation of 4-amino-1,6-anhydro-4-deoxy-β- d-manno- and -β- d-altro-pyranose

Abstract

Treatment of the title ditosylate 1 or dianhydride 2 with methanolic ammonia afforded 1,6-anhydro-3,4-dideoxy-3, 4-epimino-β- d-altropyranose ( 5) and 2,4-diamino-1,6-anhydro-2,4-dideoxy-β- d-glucopyranose via 4-amino-1,6:2,3-dianhydro-4-deoxy-β- d-mannopyranose. Acid hydrolysis of 5 gave 4-amino-1,6-anhydro-4-deoxy-β- d-mannopyranose, and treatment of the diacetyl derivative of 5 with hydrochloric acid in moist chloroform yielded 4-acetamido-3- O-acetyl-1,6-anhydro-4-deoxy-β- d-mannopyranose. Partial acylation of 5 with acetic anhydride or benzoyl chloride gave the N-acetyl or the N-benzoyl derivative, respectively. The latter compound was isomerised with sodium iodide in acetone to an oxazoline derivative, alkaline hydrolysis of which yielded 4-amino-1,6-anhydro-4-deoxy-β- d-altropyranose ( 18). The hydrochloride of 18 was prepared by treatment of 4-acetamido-1,6:2,3-dianhydro-4-deoxy-β- d-mannopyranose with hydrochloric acid in ethanol.