ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Alternative syntheses of methylated sugars. XIII. Unambiguous synthesis of methyl 2,4-di-O-methyl-α-D-galactopyranoside and methyl (methyl 2,4-di-O-methyl-α-D-galactopyranosid)uronate

P. Kováč and R. Brežný

Institute of Chemistry, Slovak Academy of Sciences, 809 33 Bratislava

Abstract:  Treatment of methyl 3,4-0-isopropylidene-2-0-methyl-a-D-galactopyranoside with benzaldehyde in the presence of boron trifluoride etherate gave a high yield of methyl 4,6-0-benzylidene-2-0-methyl- α-D-galactopyranoside I. Benzylation of/, debenzylidenation, tritylation, acetylation and methylation afforded new derivatives of methyl a-D-galactopyranoside II — VI the latter of which was the key intermediate in the synthesis of the title glycosides. One-step debenzylation and detritylation of VI gave the 2,4-di-O-methyl derivative of methyl a-D-galactopyranoside VIII and the title galacturonic acid derivative X was obtained from VI by detritylation, oxidation of the fully substituted, except HO-6, derivative VII, esterification of the formed acid followed by hydrogenolysis of the ester IX.

Full paper in Portable Document Format: 294a544.pdf

Chemical Papers 29 (4) 544–551 (1975)