Enoate Reductase-Mediated Preparation of Methyl (S)-2-Bromobutanoate, a Useful Key Intermediate for the Synthesis of Chiral Active Pharmaceutical Ingredients
摘要:
Enoate reductases belonging to the Old Yellow Enzyme (OYE) family were employed to develop a biocatalysed approach to methyl (S)-2-bromobutanoate, a key intermediate for the introduction of a particular stereogenic unit into the molecular skeleton of a certain class of chiral drugs. Methyl (Z)-2-bromocrotonate afforded, respectively, (S)-2-bromobutanoic acid (ee = 97%) and methyl (S)-2-bromobutanoate (ee = 97%) by baker's yeast fermentation and by OYE1-3 biotransformations. The bioreductions of other methyl 2-haloalkenoates were also considered. It was observed that the (Z)- and (E)-diastereoisomers of alpha-bromo unsaturated esters afforded the same enantiomer of the corresponding reduced product.
A Highly Stereoselective Synthesis of (E)-α-Bromoacrylates
作者:Keiko Tago、Hiroshi Kogen
DOI:10.1016/s0040-4020(00)00811-5
日期:2000.11
Novel reagent, methyl bis(2,2,2-trifluoroethoxy)bromophosphonoacetate (5a), was designed and prepared in order to efficiently synthesize (E)-α-bromoacrylates 7, from which widely useful precursors for various C–C bond formations were prepared. Horner–Wadsworth–Emmons (HWE) reaction of various aldehydes with 5a in the presence of t-BuOK and 18-C-6 gave corresponding (E)-α-bromoacrylate derivatives with