SYNTHESIS OF D-AMICETOSE AND L-RHODINOSE FROM L-GLUTAMIC ACID

Article abstract of DOI:10.1016/0008-6215(83)88353-0

L-Glutamic acid has been converted into a separable mixture of D-amicetono- and L-rhodinono-γ-lactones by a sequence involving transformation into (S)-γ-carboxy-γ-butyrolactone (2), conversion of 2 into the corresponding methyl ketone by the diazoketone route, and selective reduction with zinc borohydride or boranemethyl sulfide.Reduction of the two lactones with di-isobutylaluminium hydride gave the corresponding deoxy sugars.In spite of some improvements in the preparation of 2, the optical yield of this step was only ca. 80percent, but one crystallisation from chloroform raised the optical purity to 96percent.The subsequent steps produced a loss in optical purity of only 4percent.