Cotterill, Ian C.; Sutherland, Alan G.; Roberts, Stanley M.; Grobbauer, Robert; Spreitz, Josef; Faber, Kurt.
Sterically demanding bicyclo[3.2.0]hept-2-en-6-one I (R = Me) was resolved enzymically via exo-acetate II using crude porcine pancreatic lipase. By employing different fractions of hydrolases from the crude enzyme, evidence was obtained that an enzymic 'impurity' was responsible for the highly selective reaction (E > 300). Alternatively, I (R = Me, Ph) were resolved via bromohydrins III (R = Me, Ph) by lipases from Pseudomonas cepacia and Candida cylindracea but only when acylations were conducted in org. media.