Improved Synthesis of 1,2-trans-Acetates and 1,2-trans Ethyl 1-Thioglycosides Derived from 3,4,6-Tri-O-acetyl-2-deoxy-2-phthalimido-D-hexopyranosides

Abstract

Effective one-pot synthesis of 1,2-trans-acetates 4b, 5b and 6a derived from N-phthaloyl-protected D-glucosamine, D-galactosamine and D-mannosamine, respectively, is presented. Anomerisation of the corresponding 1,2-cis-acetates 4a, 5a and 6b and direct conversion of all of them to 1,2-trans ethyl 1-thioglycosides 7, 8 and 9 are also described and discussed.