A chemoenzymatic asymmetric synthesis of (+)-strictifolione
摘要:
A chemoenzymatic asymmetric synthesis of the title compound has been developed using an efficient lipase-catalyzed acylation and a chiral reagent-directed diastereoselective allylation as the key steps for incorporating the stereogenic centers. A cross metathesis was employed to obtain the required E-olefin geometry of the target compound. (C) 2012 Elsevier Ltd. All rights reserved.
The direct catalytic asymmetric aldolreaction offers efficient access to β‐hydroxy carbonyl entities. Described is a robust direct catalytic asymmetric aldolreaction of α‐sulfanyl 7‐azaindolinylamide, thus affording both aromatic and aliphatic β‐hydroxy amides with high ee values. The design of this transformation features a cooperative interplay of a soft and a hard Lewisacid, which together facilitate
[R′CH(OH)CHCHCO2R], which are ubiquitous structures in biologically active natural products and useful building blocks for organicsynthesis of chiral compounds. From the optically pure (R)-2-(2-benzothiazolylsulfinyl)acetates (>99% ee) prepared by the enzymatic kinetic resolution of (±)-2-(2-benzothiazolylsulfinyl)acetates, opticallyactive 4-hydroxyalk-2-enoates (up to 91% ee) have been obtained in good
Asymmetric synthesis of (S)-vigabatrin® and (S)-dihydrokavain via cobalt catalyzed hydrolytic kinetic resolution of epoxides
作者:I. Victor Paul Raj、A. Sudalai
DOI:10.1016/j.tetlet.2008.02.064
日期:2008.4
A concise route to the asymmetricsynthesis of (S)-vigabatrin® and (S)-dihydrokavain has been described using Co-catalyzed hydrolytic kinetic resolution of racemic epoxides and regiospecific opening of terminal epoxides with dimethylsulfonium methylide as the key steps.
Enantioselective Total Synthesis of Diocollettines A
作者:Yuichiro Kawamoto、Toyoharu Kobayashi、Hisanaka Ito
DOI:10.1021/acs.orglett.9b01776
日期:2019.8.2
The first enantioselectivetotalsynthesis of diocollettines A was accomplished in only six steps from a known compound. A short and practical synthetic route was disclosed, featuring an intensive investigation of the stereoselective aldol reaction as a key step using an easily prepared aldehyde moiety and an enone derivative. The synthetic scheme also includes the efficient stereocontrolled construction
Total Synthesis of (−)-Blepharocalyxin D and Analogues
作者:Benjamin D. Cons、Adam J. Bunt、Christopher D. Bailey、Christine L. Willis
DOI:10.1021/ol400736w
日期:2013.4.19
An efficient strategy for the total synthesis of (-)-blepharocalyxin D and an analogue is described. The key step involves an acid-mediated cascade process in which reaction of methyl 3,3-dimethoxypropanoate with gamma,delta-unsaturated alcohols possessing diastereotopic styrenyl groups gives trans-fused bicyclic lactones with the creation of two rings and four stereocenters in one pot.