SYNTHESIS OF 3,6-DIDEOXY-3-(METHYLAMINO)HEXOSES FOR G.L.C.-M.S. IDENTIFICATION OF RHIZOBIUM LYPOSACCHARIDE COMPONENTS

Article abstract of DOI:10.1016/S0008-6215(00)90026-0

A direct synthetic route from methyl α-D-glucopyranoside to 3,6-dideoxy-3-(methylamino)hexoses having the D-gluco, D-galacto, and D-manno configurations has been developed.Methyl α-D-glucoside was converted into the 4,6-O-benzylidene-2,3-di-O-tosyl derivative, which was then transformed into the 4-O-benzyl-6-deoxy 2,3-ditosylate (5) by successive reductive cleavage of the acetal ring, iodination, and reduction.The intermediate 5 was readily converted into the allo 2,3-epoxide, which yielded the pivotal intermediate methyl 4-O-benzyl-3,6-dideoxy-3-(methylamino)-α-D-glucopyranoside (7) by cleavage of the oxirane ring with methylamine.The amino compound 7 can be directly converted into the derivatized galacto and manno derivatives for mass-spectrometric identification by selective inversion at C-4 and C-2, respectively, followed by hydrolysis, reduction, and acetylation.