Synthesis of bis-(methyl 3,4,6-tri-O-acetyl-D-glucopyranosid-2-yl)-oxamides

The synthesis of a new bis-(D-glucopyranosid-2-yl)oxamides via the key intermediate, N-acetyl N-(methyl 3,4,6-tri-O-acetyl-alpha-D-glucopyranosid-2-yl) oxamic acid chloride (2alpha) is described. Treatment of compound 2alpha with methyl 3,4,6-tri-O-acetyl-2-amino-2-deoxy-beta-D-glucopyranoside afforded N-(methyl 3,4,6-tri-O-acetyl-alpha-D-glucopyranosid-2-yl)-N'-(methyl 3,4,6-tri-O-acetyl-beta-D-glucopyranosid-2-yl)-oxamide. Reaction of 2alpha with 1,2-diaminoethane afforded 1,2-bis-[N,N'-(methyl 3',4',6'-tri-O-acetyl-alpha-D-glucopyranosid-2'-yl)]ethyloxamide as a main product, while 2-N-[N'-(methyl 3',4',6'-tri-O-acetyl-alpha-D-glucopyranosid-2'-yl)oxamide]-ethyl acetamide was formed as a side product. Reaction of 2alpha with 1,3-diamino-2-hydroxypropane gave only 1,3-bis-N,N-[N'-(methyl 3',4',6'-tri-O-acetyl-2'-deoxy-alpha-D-glucopyranosid-2'-yl)-oxamido]-2-propanol.

Synthesis and solid state 13C and 1H NMR analysis of new oxamide derivatives of methyl 2-amino-2-deoxy-alpha-D-glucopyranoside and ester of amino acids or dipeptides

The syntheses of new oxamide derivatives of methyl 2-amino-2-deoxy-alpha-D-glucopyranoside and amino acid or peptide esters are presented. The reaction of methyl 3,4,6-tri-O-acetyl-2-acetamido-2-deoxy-alpha-D-glucopyranoside and oxalyl chloride gave N-(methyl 3,4,6-tri-O-acetyl-2-deoxy-alpha-D-glucopyranosid-2-yl) oxamic acid chloride which on reaction with the ester of Gly, L-Ala, L-Phe, GlyGly, Gly-L-Phe and Gly-L-Ala afforded N-(methyl 3,4,6-tri-O-acetyl-2-deoxy-alpha-D-glucopyranosid-2-yl), N'-oxalyl-amino acid or dipeptide esters. The structure of the oxamides was studied using 1H, 13C NMR in solution and solid state.

Crystal structure and solid state 13C NMR analysis of N-(methyl 3,4,6-tri-O-acetyl-alpha, and beta-D-glucopyranosid-2-yl)-oxamide derivative of p-chloroaniline, N,N-diethylamine, N-methylaniline and N-ethylaniline

The X-ray diffraction analysis of N-(methyl 3,4,6-tri-O-acetyl-alpha-D-glucopyranosid-2-yl)-N'-p-chlorophenyloxamide (1), N-(methyl 3,4,6-tri-O-acetyl-alpha-D-glucopyranosid-2-yl)-N',N'-diethyloxamide (2), N-acetyl, N-(methyl 3,4,6-tri-O-acetyl-beta-D-glucopyranosid-2-yl), N'-methyl, N'-phenyloxamide (3), N-acetyl, N-(methyl 3,4,6-tri-O-acetyl-beta-D-glucopyranosid-2-yl), N'-ethyl, N'-phenyloxamide (4) was performed. It was found that the oxamide group in compounds 1-4 can be characterized as two structurally independent amides because there is no pi conjugation across the oxalyl OC-CO bond. Only the oxamide group of 1 is planar and adopts trans conformation stabilized as two intramolecular N-H...O hydrogen bonds.