Stereospecific synthesis of novel methyl-substituted mono- and di-methoxy conduritols

Methyl-monomethoxy conduritol-B and methyl-dimethoxy conduritol-B were synthesized starting from 2-methylbenzo-1,4-quinone. Bromination of 2-methylbenzo-1,4-quinone was followed by the reduction of the carbonyl groups with NaBH4 to give a dioldibromo compound. Methyl-dimethoxy conduritol-B was synthesized from the reaction of the dioldibromo compound with CH3ONa, followed by acetylation with Ac2O-pyridine to obtain methyl-dimethoxy diacetate. On the other hand, acetylation of the methyl-dioldibromo compound followed by reaction with LiOH gave a monoepoxide compound stereoselectively. The reaction of the epoxide with H+/Ac2O afforded the monobromo triacetate. Controlled reaction of monobromo-triacetate with CH3ONa in MeOH furnished the desired new methyl-monomethoxy conduritol-B. The structures of all synthesized compounds were characterized by spectroscopic methods.