tested in the microbial reduction of methyl-substituted bicyclo[3.2.0]hept-3-en-6-ones 1a-c. The endo-alcohols 2a-c were obtained with good yields and enantiomeric excess. Lower yields are described for the exo-alcohols 3a-c which are normally enantiomerically pure. Comparisons with microbial reduction of bicyclo[3.2.0]hept-2-en-6-one 1d and bicyclo[3.3.0]oct-7-en-2-one 1e are also reported.
The reduction of bicyclo[3.2.0]hept-3-en-6-ones 1a,b with Baker’s yeast to a mixture of enantiomerically pure (6S)-endo- and (6S)-exo-alcohols 2a,b and 3a,b respectively is described. Furthermore the oxidation of the racemic endo-alcohols 2a,b with Bacillus stearothermophilus afforded the corresponding ketones with high enantiomeric excesses resolving the endo-enantiomer. In the same conditions the