The dynamic kinetic resolution of 3-oxo-4-phenyl-β-lactam by recombinant E. coli overexpressing yeast reductase Ara1p
摘要:
Using a recombinant E coli strain overexpressing yeast reductase Ara 1 p, we reduced racemic 3-oxo-4-phenyl-beta-lactam to cis-(3S,4R)-3-hydroxy-4-phenyl-beta-lactam as a single enantiopure product. The dynamic kinetic resolution occurred over the course of fermentation at pH 7. Under the same conditions, 3-oxo-4-(2-thiophenyl)-beta-lactam 4 and 3-oxo-4-(2-furyl)-beta-lactam 5 were not resolved. (c) 2005 Elsevier Ltd. All rights reserved.
Preparation of .alpha.-Methylene and .alpha.-Ethylidene .beta.-Lactams via the Ester Enolate-Imine Condensation Using .beta.-(Dialkylamino) Esters as Starting Materials: Scope and Synthetic Applications
A new, simple procedure for the preparation of appropriately substituted alpha-methylene and alpha-ethylidene beta-lactams via the ester enolate-imine condensation is described. The method is based on the use of lithium 3-(dialkylamino) ester enolates as synthetic equivalents of the corresponding acrylate alpha-anions. Thus, the reaction of lithium enolates of 3-(dialkylamino) esters with imines produced alpha-[(dialkylamino)alkyl] beta-lactams stereoselectively and in high yield. Upon dehydroamination the latter furnished a variety of alpha-alkylidene beta-lactams. The synthesis of 3-alkylidene-4-formyl-2-azetidinones is a particularly significant feature of this work. Preparation of functionalized alpha-keto beta-lactams and beta-lactam-furan hybrids through a dihydroxylation-oxidation process starting from different alpha-alkylidene derivatives is also described. In addition, reduction of various 4-functionalized (Z)- and (E)-3-ethylidene-2-azetidinones yielded the corresponding 3-ethylideneazetidines as advanced precursors of polyoximic acids.
Mihovilovic, Marko D.; Feicht, Anton; Kayser, Margaret M., Journal fur Praktische Chemie (Weinheim), 2000, vol. 342, # 6, p. 585 - 590
作者:Mihovilovic, Marko D.、Feicht, Anton、Kayser, Margaret M.
DOI:——
日期:——
Ni-Catalyzed asymmetric reduction of α-keto-β-lactams <i>via</i> DKR enabled by proton shuttling
Chiral α-hydroxy-β-lactams are key fragments of many bioactive compounds and antibiotics, and the development of efficient synthetic methods for these compounds is of great value. The highly enantioselective dynamic kinetic resolution (DKR) of α-keto-β-lactams was realized via a novel proton shuttling strategy. A wide range of α-keto-β-lactams were reduced efficiently and enantioselectively by Ni-catalyzed
The dynamic kinetic resolution of 3-oxo-4-phenyl-β-lactam by recombinant E. coli overexpressing yeast reductase Ara1p
作者:Yan Yang、Melissa Drolet、Margaret M. Kayser
DOI:10.1016/j.tetasy.2005.07.029
日期:2005.8
Using a recombinant E coli strain overexpressing yeast reductase Ara 1 p, we reduced racemic 3-oxo-4-phenyl-beta-lactam to cis-(3S,4R)-3-hydroxy-4-phenyl-beta-lactam as a single enantiopure product. The dynamic kinetic resolution occurred over the course of fermentation at pH 7. Under the same conditions, 3-oxo-4-(2-thiophenyl)-beta-lactam 4 and 3-oxo-4-(2-furyl)-beta-lactam 5 were not resolved. (c) 2005 Elsevier Ltd. All rights reserved.