Baker's yeast mediated stereoselective biotransformation of 1-acetoxy-3-aryloxypropan-2-ones
摘要:
A series of 1-acetoxy-3-aryloxypropan-2-ones la-m were synthesized and subjected to biotransformation by baker's yeast yielding optically active monoacetates 5 or ent-5 and/or diols 4 of moderate to excellent enantiomeric purity. The dependence of the reduction/hydrolysis ratio and stereoselectivity on the size and substitution pattern of the aromatic moiety in the substrate is also discussed. (C) 1998 Elsevier Science Ltd. All rights reserved.
A method for the kinetic resolution of 3-(aryloxy)-1,2-propanediols rac-1a-n without additional protection-deprotection steps using a lipase-catalyzed sequential transesterification with lipase amnno PS has been developed. In the first step of this one-pot procedure the racemic 1,2-diols are acylated regioselectively at the primary hydroxy group without enantioselection. The subsequent acylation at the secondary hydroxy group of the formed primary monoacetate is responsible for high enantioselection. The enantioselectivity of this transformation depends significantly on the substitution pattern of the aryl ring and the organic solvent used. 3-(Aryloxy)-1,2-propanediols with substituents in the para-position show a much higher enantioselectivity than the corresponding derivatives with ortho-substituents. Among other substrates, the pharmaceuticals Mephenesin, Guaifenesin, and Chlorphenesin have been resolved. The replacement of the aryloxy by alkyl substituent causes a dramatic decrease of enantioselectivity.
Baker's yeast mediated stereoselective biotransformation of 1-acetoxy-3-aryloxypropan-2-ones
A series of 1-acetoxy-3-aryloxypropan-2-ones la-m were synthesized and subjected to biotransformation by baker's yeast yielding optically active monoacetates 5 or ent-5 and/or diols 4 of moderate to excellent enantiomeric purity. The dependence of the reduction/hydrolysis ratio and stereoselectivity on the size and substitution pattern of the aromatic moiety in the substrate is also discussed. (C) 1998 Elsevier Science Ltd. All rights reserved.
A biocatalytic approach for regioselective monoacetylation of 3-aryloxy-1,2-propanediols by porcine pancreatic lipase
作者:Vachan Singh Meena、U. C. Banerjee
DOI:10.1007/s00706-011-0688-y
日期:2012.6
AbstractAmong the various lipases screened for the regioselective monoacetylation of 3-aryloxy-1,2-propanediols, porcine pancreatic lipase was found to afford a higher yield. The selectivity for the monoacetylation process was maximized by using different organic solvents and diisopropyl ether gave the highest conversion to monoacetylated product (ca. 98%). The optimized reaction afforded excellent