D. Cicero, O. Varela, R. Lederkremer
1990
Citations
0
Influential Citations
17
Citations
Journal
Tetrahedron
Abstract
Abstract The synthesis of pyranoid and furanoid derivatives of 6-deoxy-4-thio- D -galactose from methyl α- D -glucopyranoside ( 1 ) is described. A key intermediate for the synthesis, methyl 2,3-di- O -benzoyl-6-deoxy-4-thio-α- D -galactopyranoside ( 15 ) was prepared by different approaches from 1 . Regioselectivity for the protection or modification of the hydroxyl groups of 1 or its derivatives was achieved by employing various reagents. The thiol group at C-4 was introduced by nucleophilic substitution of a tosylate by thiocyanate followed by reduction or alkaline methanolysis of the thiocyano group. A by-product of the latter reaction was characterized as a monothiolcarbonate derivative ( 17 ), whose conformation was studied by molecular mechanics calculations. Acetolysis of methyl 6-deoxy-4-thio-α- D -galactopyranoside ( 16 ) afforded ring sulfur containing derivatives of 6-deoxy-4-thio- D -galactofuranose, which are described for the first time.