The Synthesis of Diosgenyl 2-Amino-2-deoxy-β-D-glucopyranoside Hydrochloride.

Abstract The N -trifluoroacetyl- and N -tetrachlorophthaloyl-protected bromide of d -glucosamine has been used for the first time as a glycosyl donor for the glycosylation of diosgenin [(25 R )-spirost-5-en-3β-ol]. Both 1,3,4,6-tetra- O -acetyl-2-deoxy-2-trifluoroacetamido-β- d -glucopyranoside and 1,3,4,6-tetra- O -acetyl-2-deoxy-2-tetrachlorophthalimido-α,β- d -glucopyranoside were transformed into the appropriate glycosyl bromides. These reacted with diosgenin under mild conditions, using silver triflate as a promoter, and gave the corresponding protected diosgenyl glycosides. Each was deprotected to give diosgenyl 2-amino-2-deoxy-β- d -glucopyranoside hydrochloride. The structures of the new glycosides were established by 1 H NMR spectroscopy.