Lipase-Catalyzed Kinetic Resolution of γ-Hydroxy Phenyl Sulfones

Article abstract of DOI:10.1021/jo00040a028

Lipase PS (from Pseudomonas cepacia) catalyzed the enantioselective transesterification of racemic γ-hydroxy-α,β-unsaturated phenyl sulfones 1 and their α,β-saturated derivatives 3 with vinyl acetate in an organic solvent (usually ⁱPr2O).Remarkably, in substrates 1 with (E)-stereochemistry, the enantioselectivity of the process was little influenced by the nature of the R chain.Hence, very high enantiomeric ratios (E>/=45) were observed in substrates 1 bearing short (R = Me or Et), long (R = n-C6H13 or n-C10H21), bulky (R = ⁱPr), or functionalized R chains.The (R)-enantiomer was the fast-reacting enantiomer in all cases.Concerning the reactivity, the rate of the reaction decreased significantly with an increase in size of length of the R chain (reaction time for 50percent conversion from 3.5 to 162 h).Less satisfactory enantioselectivities (E = 5-48) were obtained when the saturated substrates 3 were used instead of the corresponding α,β-unsaturated alcohols 1.