Studies on the synthesis of propyl 4-O-beta-D-galactopyranosyl-alpha-D-galactopyranoside

Carbohydr Res. 1984 Aug 15;131(2):227-38. doi: 10.1016/0008-6215(84)85244-1.

Abstract

2-O-Benzoyl-3,6-di-O-benzyl-4-O-(chloroacetyl)-, 4-O-acetyl-2-O-benzoyl-3,6-di-O-benzyl-, and 2-O-benzoyl-3,4,6-tri-O-benzyl-alpha-D-galactopyranosyl chloride were converted into the corresponding 2,2,2-trifluoroethanesulfonates, and these were treated with allyl 2-O-benzoyl-3,6-di-O-benzyl-alpha-D-galactopyranoside, to give allyl 2-O-benzoyl-4-O-[2-O-benzoyl-3,6-di-O-benzyl-4-O-(chloroacetyl)- beta-D-galactopyranosyl]-3,6-di-O-benzyl-alpha-D-galactopyranoside (26; 41% yield), allyl 4-O-(4-O-acetyl-2-O-benzoyl-3,6-di-O-benzyl-beta-D- galactopyranosyl)-2-O-benzoyl-3,6-di-O-benzyl-alpha-D-galactopyranoside (27; 62% yield), and allyl 2-O-benzoyl-4-O-(2-O-benzoyl-3,4,6-tri-O-benzyl-beta-D- galactopyranosyl)-3,6-di-O-benzyl-alpha-D-galactopyranoside (28; 65% yield). All disaccharides were free from their alpha anomers. Disaccharides 26 and 27 were found to be base-sensitive, and were de-esterified by KCN in aqueous ethanol, and debenzylated with H2-Pd. Attempts to produce (1----4)-beta-D-galactopyranosides from the coupling of a number of fully esterified D-galactopyranosyl sulfonates to allyl 2,3,6-tri-O-benzoyl-alpha-D-galactopyranoside were unsuccessful.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Disaccharides / chemical synthesis*
  • Magnetic Resonance Spectroscopy
  • Stereoisomerism

Substances

  • Disaccharides
  • 1-propyl-4-O-beta galactopyranosyl-alpha galactopyranoside