Abstract 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, conversion of 2 into the corresponding methyl ketone by the diazoketone route, and selective reduction with zinc borohydride or borane-methyl sulfide. Reduction of the two lactones with di-isobutylaluminium