Studies towards dynamic kinetic resolution of 4-hydroxy-2-methylcyclopent-2-en-1-one and its E-O-trityloxime

Dynamic kinetic resolution through metal complex induced racemization and Candida antarctica lipase mediated enantioselective acetylation of a model hydroxy-ketone: 4-hydroxy-2-methylcyclopent-2-en-1-one and its selected derivatives, has been studied. Racemization of the hydroxy-ketone was efficiently affected by [RuCl2(cymene)]2 complex-triethylamine while Shvo's catalyst triggered an intramolecular redox process. Kinetic resolution of 4-hydroxy-2-methylcyclopent-2-en-1-one with C. antarctica under conditions compatible with [RuCl2(cymene)]2 racemization failed to reach the efficiency threshold. However, dynamic kinetic resolution of its O-trityloxime using [RuCl2(cymene)]2-triethylamine and C. antarctica lipase-isopropenyl acetate combination, was successfully achieved.

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