Synthesis of mirror coryno cord factors

Article abstract of DOI:10.1016/0008-6215(93)80100-S

A protected bis-heptosiduronic acid, (2,3,4-tri-O-benzyl-6-deoxy-α-D-gluco-heptopyranosyluronic acid) 2,3,4-tri-O-benzyl-6-deoxy-α-D-gluco-heptopyranosiduronic acid, was synthesized by the iron carbonyl method of chain elongation, starting from 2,3,4,2',3',4'-hexa-O-benzyl-6,6'-di-O-tosyl-α,α-trehalose.Its dimethyl ester was also prepared by acid-catalyzed methanolysis of its diamide, previously obtained by another route.Mitsunobu esterification of the diacid with (racemic) (2RS,3SR)- and (2RS,3RS)-3-O-benzylcorynomycolyl alcohols, obtained by reduction of synthetic, 3-O-benzylated methyl C₃₂-corynomycolates with lithium aluminum hydride, furnished the corresponding diesters in high yields.Hydrogenolytic debenzylation of the products led to "mirror" coryno cord factors.