Enzymatic desymmetrisation of conduritol D. Preparation of homochiral intermediates for the synthesis of cyclitols and aminocyclitols

From meso-conduritol D tetraacetate four homochiral partial derivatives, namely (+)-(1R,2R,3S,4S)-1-hydroxy-2,3,4-triacetoxy-5-cyclohexene, (-)-(1R,2R,3S,4S)-2-hydroxy-1,3,4-triacetoxy-5-cyclohexene, (-)-(1R,2R,3S,4S)-1-benzoyloxy-3,4-diacetoxy-2-hydroxy-5-cyclohexene and (+)-(1R,2R,3S,4S)-3,4-diacetoxy-1,2-dihydroxy-5-cyclohexene, have been prepared through enzymatic reactions catalysed by one of the following lipases: from porcine pancreas, from Mucor miehei and from Candida cylindracea. These compounds are of potential utility in the synthesis of cyclitols and aminocyclitols. As an example, the preparation of the previously unreported (+)-conduramine C-4 is also reported.