SYNTHESIS OF DESTOMIC AND epi-DESTOMIC ACID, AND THEIR C-6 EPIMERS

Article abstract of DOI:10.1016/S0008-6215(00)82223-5

Four stereoisomers of 6-amino-6-deoxyheptonic acid, having the L-glycero-D-galacto (1), D-glycero-D-galacto (2), L-glycero-D-gluco (3), and D-glycero-D-gluco(4) configurations, were synthesized from D-galacto- (8) and D-gluco-dialdose (23) derivatives, respectively.Cyanomesylation of 8 and 23 gave two C-6 epimers, respectively, which were separately converted, via the corresponding 6,7-epimino derivatives, into 6-(benzyloxycarbonyl)amino-6-deoxy derivatives by reduction with lithium aluminium hydride, N-(benzyloxycarbonyl)ation, and acetolysis with acetic acid.After deprotection of each hemiacetal, the stereoisomers were oxidized with bromine, followed by total deprotection, to give 1-4.Among these products, 1 and 3 proved to be identical with the naturally occuring destomic and epi-destomic acid obtained from antibiotic destomycins.