Lipase-catalyzed kinetic resolution of .gamma.-hydroxy phenyl sulfones
摘要:
Lipase PS (from Pseudomonas cepacia) catalyzed the enantioselective transesterification of racemic gamma-hydroxy-alpha,beta-unsaturated phenyl sulfones 1 and their alpha,beta-saturated derivatives 3 with vinyl acetate in an organic solvent (usually (i)Pr2O). 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 greater-than-or-equal-to 45) were observed in substrates 1 bearing short (R = Me or Et), long (R = n-Cr6H13 or n-C10H21), bulky (R = (i)Pr), 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 or length of the R chain (reaction time for 50% 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 alpha,beta-unsaturated alcohols 1.
An efficient preparation of optically active (E)-γ-hydroxy-α,β-unsaturated phenyl sulfones using lipase-mediated acylations
作者:Esteban Domínguez、Juan Carlos Carretero、Alfonso Fernández-Mayoralas、Santiago Conde
DOI:10.1016/s0040-4039(00)93455-5
日期:1991.9
(E)-gamma-Hydroxy-alpha,beta-unsaturated phenyl sulfones have been efficiently resolved via irreversible enzymatic acylation with lipase PS (pseudomonas cepacia) and vinyl acetate. This process has been applied to the synthesis of the aggregation pheromone (-)-(3S,4S)-4-methyl-3-heptanol.
Lipase-catalyzed kinetic resolution of .gamma.-hydroxy phenyl sulfones
作者:Juan C. Carretero、Esteban Dominguez
DOI:10.1021/jo00040a028
日期:1992.7
Lipase PS (from Pseudomonas cepacia) catalyzed the enantioselective transesterification of racemic gamma-hydroxy-alpha,beta-unsaturated phenyl sulfones 1 and their alpha,beta-saturated derivatives 3 with vinyl acetate in an organic solvent (usually (i)Pr2O). 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 greater-than-or-equal-to 45) were observed in substrates 1 bearing short (R = Me or Et), long (R = n-Cr6H13 or n-C10H21), bulky (R = (i)Pr), 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 or length of the R chain (reaction time for 50% 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 alpha,beta-unsaturated alcohols 1.