Lipase-catalysed resolution by an esterification reaction in organic solvent of axially chiral (+/-)-3,3 '-bis(hydroxymethyl)-2,2 '-bipyridine N,N-dioxide

The enzymatic kinetic resolution of atropisomeric (±)-3,3?-bis(hydroxymethyl)-2,2?-bipyridine N,N-dioxide (±)-3 was investigated via enantioselective esterification in the unusual medium of alcohol/vinyl acetate (20:80). Lipase from Mucor miehei (immobilised lipase preparation, Lipozyme®) was found to give good enantioselectivity with an (aS)-enantiopreference in the axial recognition, and allowed to efficiently perform the preparation of both enantioforms with ee >98%. Lipase from Pseudomonas cepacia (immobilised lipase preparation, PS-D) also catalysed the reaction although with low enantioselectivity and showing opposite stereopreference.