STRUCTURE AND REARRANGEMENT REACTIONS OF SOME DIGLYCOSYLAMINES

Article abstract of DOI:10.1016/0008-6215(87)80130-1

Di-β-D-glucopyranosylamine (2) was prepared by transglycosylation from β-D-glucopyranosylamine.O-Acetylation of 2 led to partial anomerization and the formation of the expected octa-O-acetyl β,β derivative and its α,β anomer in the ratio 1:2,4.Similarly, transglycosylation of β-D-xylopyranosylamine afforded di-β-D-xylopyranosylamine (7).As with 2, the O-acetylation of 7 led to partial anomerization and formation of the hexa-O-acetyl α,β anomer of 7, as well as the expected β,β O-acetylated derivative.O-Deacetylation with ammonia in methanol of (2,3,4-tri-O-acetyl-α-D-xylopyranosyl)(2,3,4-tri-O-acetyl- β-D-xylopyranosyl)amine (7) led to recovery of the β,β-linked starting material.These rearrangement reactions are interpreted in terms of unfavorable nonbonded interactions which modify the thermodynamic equilibrium of the diglycosylamines.