An efficient asymmetric synthesis of the C₂₂-trihydroxy fatty acid component of macroviracin A has been developed. The key steps were highly enantioselective (i) lipase-catalyzed acylation, (ii) InCl₃-(S)-BINOL mediated allylation, and (iii) asymmetric dihydroxylation (ADH) reaction. The moderate diaster-eoselectivity of the ADH reaction was overridden by converting the resultant diol diastereomers to the required epoxide enantiomer.