A NOVEL METHOD FOR THE GENERATION OF AN ESTER ENOLATE ANION FROM ETHOXYACETYLENE
作者:Teruaki Mukaiyama、Masahiro Murakami
DOI:10.1246/cl.1981.1129
日期:1981.8.5
An ester enolate anion was generated in situ by the successive treatment of ethoxyacetylene with mercury(II) chloride, pyridine-1-oxide and zinc dust, and the zinc enolate thus formed further reacted with aldehydes to give α-chloro-β-hydroxyesters.
Synthesis of (2<i>S</i>)-2-Chloro-2-fluororibolactone via Stereoselective Electrophilic Fluorination
作者:Coralie De Schutter、Ozkan Sari、Steven J. Coats、Franck Amblard、Raymond F. Schinazi
DOI:10.1021/acs.joc.7b02245
日期:2017.12.15
A novel and efficient route for the preparation of (2S)-2-chloro-2-fluorolactone 29 is described. This approach takes advantage of a highly efficient diastereoselective electrophilicfluorination reaction (94% yield; >50:1 dr)
A new dehydrogenase from Clostridium acetobutylicum for asymmetric synthesis: dynamic reductive kinetic resolution entry into the Taxotère side chain
作者:Gregory A. Applegate、Ross W. Cheloha、David L. Nelson、David B. Berkowitz
DOI:10.1039/c0cc04585c
日期:——
has been expressed and characterized. CaADH enantioselectively reduces aromatic alpha-, beta- and gamma-keto esters to the corresponding D-hydroxy esters and provides a building block for the Taxoteresidechain (95% yield, 95% de, 99% ee) by dynamic reductive kinetic resolution (DYRKR).
Enantiodivergent, Biocatalytic Routes to Both Taxol Side Chain Antipodes
作者:Brent D. Feske、Iwona A. Kaluzna、Jon D. Stewart
DOI:10.1021/jo0516077
日期:2005.11.1
N-benzoyl phenylisoserine Taxol sidechain. After base-mediated ring closure of the chlorohydrin enantiomers, the epoxides were converted directly to the oxazoline form of the target molecules using a Ritter reaction with benzonitrile. These were hydrolyzed to the ethyl ester form of the Taxol sidechain enantiomers under acidic conditions. This brief and atom-efficient route to both target enantiomers
Asymmetric Reduction of 2-Chloro-3-oxo Esters by Transfer Hydrogenation
作者:Jinjin Bai、Shifeng Miao、Yun Wu、Yawen Zhang
DOI:10.1002/cjoc.201180419
日期:2011.11
Asymmetric reduction of 2‐chloro‐3‐oxoesters was achieved by catalytic transfer hydrogenation using [RuCl2(p‐cymene)](S,S)‐TsDPEN as the chiral catalyst and HCOOH‐Et3N as the hydrogen source. Moderate to good yields (up to 85%) and good enantioselectivities (up to 98% ee) were obtained.