Synthesis of 1d-(1,3,5/2,4)-4-acetamido-5-amino-1,2,3-cyclohexanetriol and its incorporation into a pseudo-disaccharide

✍ Scribed by Lai-Xi Wang; Nobuo Sakairi; Hiroyoshi Kuzuhara

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 816 KB
• Volume: 275
• Category: Article
• ISSN: 0008-6215
• DOI: 10.1016/0008-6215(95)00146-k

✦ Synopsis

The synthesis of the title compound and lo-(1,3,5/2,4)-4-acetamido-5-amino-3-O-( fl-o-glucopyranosyluronic acid)-l,2,3-cyclohexanetriol is described. Starting from methyl 2-acetamido-2-deoxy-a-o-glucopyranoside 2L-(2,4,5/3)-4-acetamido-3-benzoyloxy-2-benzyloxy-5 -hydroxycyclohexanone was prepared via a series of transformations including the regioselective ring opening of the benzylidene acetal and the mercury(II)-catalyzed carbocyclic ring closure reaction of 5-enopyranoside. Stereoselective reduction of ketone 11 with NaBH(OAc) 3 gave 10-(1,2,4/3,5)-2acetamido-3-O-benzoyl-4-O-benzyl-l,3,4,5-cyclohexanetetrol (88%), which was then converted into 10-(1,3,5/2,4)-4-acetamido-5-azido-3-O-benzoyl-2-O-benzyl-l-O-pivaloyl-1,2,3-cyclohexanetriol through selective 5-OH protection, 1-O-mesylation, and subsequent azide displacement. Saponification and hydrogenation of this gave the title compound. Selective O-debenzoylation with 1.1 equiv of K2CO 3 in MeOH gave 1o-(1,3,5/2,4)-4-acetamido-5-azido-2-O-benzyl-1-O-pivaloyl-l,2,3-cyclohexanetriol (73%). Glycosylation of this compound with methyl (2,3,4-tri-O-acetyl-a-D-glucopyranosyl bromide)uronate in CHzC12, using silver triflate as the promoter, afforded lo-(1,3,5/2,4)-4-acetamido-5-azido-2-O-benzyl-3-O-(methyl 2,3,4-tri-O-acetyl-fl-D-glu-* Corresponding author.