Accession Number:

AD0618809

Title:

SYNTHESIS OF BETA-D-MANNOSE 1,2ORTHOACETATES,

Descriptive Note:

Corporate Author:

NATIONAL RESEARCH COUNCIL OF CANADA SASKATOON (SASKATCHEWAN) PRAIRIE REGIONAL LAB

Personal Author(s):

Report Date:

1965-02-04

Pagination or Media Count:

7.0

Abstract:

Synthesis of 3,4,6-tri-O-acetyl-beta-D-mannopyranose 1,2-orthoacetates I from 2,3,4,6-tetra-O-acetyl-alphaD-mannopyranosyl bromide II and various alcohols in the presence of pyridine and substituted pyridines is described. 2,6-Lutidine is a particularly effective acid acceptor in these condensations, and the use of chloroform as a diluent is advantageous. The lutidine-buffered system has afforded a good yield of orthoacetate I with several alcohols that barely react with II in the presence of silver ion this difference is attributed to the dominance of side reactions under the latter conditions. The N-bases also promote a more highly stereo-selective orthoester synthesis than does the silver-catalyzed reaction, leading to formation of the OR-exo-diastereoisomer almost exclusively. Author

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Distribution Statement:

APPROVED FOR PUBLIC RELEASE