148153-94-0Relevant articles and documents
Preparation of Sulfur-Containing Optically Active Secondary Alcohols Based on Pichia farinosa-Catalyzed anti-Prelog-Rule Reduction as the Key Step
Ohtsuka, Yoshikazu,Katoh, Osamu,Sugai, Takeshi,Ohta, Hiromichi
, p. 483 - 491 (2007/10/03)
A Pichia farinosa IAM 4682 mediated reduction of sulfur containing ketones afforded secondary alcohols with (R)-absolute configuration. For example, 4-(phenylthio)-2-butanone and 4-(phenylsulfonyl)-2-butanone afforded (R)-4-(phenylthio)-2-butanol (91%ee) in 90% yield and (R)-4-(phenylsulfonyl)-2-butanol (97%ee) in 94% yield, respectively. In the case that the ee of the product was not satisfactory, any contaminating (S)-enantiomer was selectively oxidized by Rhodococcus rhodochrous IFO 15564 to leave pure (R)-enantiomer. The substrate specificity of Pichia farinosa-mediated reduction and Rhodococcus rhodochrous-mediated oxidation was further examined.
Lipase-Catalyzed Kinetic Resolution of γ-Hydroxy Phenyl Sulfones
Carretero, Juan C.,Dominguez, Esteban
, p. 3867 - 3873 (2007/10/02)
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.
