A Novel Method for the Synthesis
of Thioacetates Using Benzyltriethylammonium Tetrathiomolybdate
and Acetic Anhydride
作者:Srinivasan Chandrasekaran、Nasir Baig. R.B.、Sai Sudhir. V.
DOI:10.1055/s-0028-1083517
日期:——
Herein we report a simple and efficient methodology for the synthesis of thioacetates using benzyltriethylammonium tetrathiomolybdate and acetic anhydride as the key reagents, starting from alkyl halides in a multistep, tandem reaction process. Its application in the synthesis of orthogonally protected cysteine and anomeric β-thioglycosides has also been demonstrated.
A Short Synthetic Approach to Chiral Serine Azido Derivatives
作者:Gautam Panda、N. Venugopal Rao
DOI:10.1055/s-2004-817770
日期:——
We report a new synthetic methodology for the synthesis of chiral serine azido derivatives through a conversion of N-protected (Boc, Cbz and Fmoc) serine amino acid into its corresponding Weinreb amide. Thus, acidity of the α-proton of the serine is reduced and it allows nucleophilic addition reaction onto Weinreb amide to furnish chiral serine azido derivatives.
Process for producing optically active cysteine derivatives
申请人:Kaneka Corporation
公开号:US20020169337A1
公开(公告)日:2002-11-14
A process for producing optically active cysteine derivatives with high optical purity and good quality which is economically advantageous and is high in productivity even on a commercial scale is provided.
A process for producing an optically active cysteine derivative which comprises synthesizing a D-form or L-form optically active cysteine derivative of the general formula (2) shown below (R
1
represents an amino-protecting group of the urethane or acyl type, R
0
represents a hydrogen atom or, taken together with R
1
, an amino-protecting group, R
2
represents an alkyl, aryl or aralkyl group, R
3
represents a univalent organic group and * represents the position of an asymmetric carbon) by reacting the corresponding D-form or L-form optically active amino acid derivative of the general formula (1) shown below with an alcohol of the general formula (3) shown below and a strong acid and/or a thionyl halide and recovering the above cysteine derivative (2) from the reaction mixture, the procedural series from reaction to recovery being carried out under conditions such that the medium contacting the above optically active cysteine derivative (2) is within the range from acidic to weakly basic to thereby recover the above cysteine derivative (2) from the reaction mixture while suppressing the decomposition and racemization thereof.
1
Preparation of S-aryl-cysteine and its derivatives
申请人:Roche Colorado Corporation
公开号:US06765109B1
公开(公告)日:2004-07-20
The present invention provides a method for preparing S-aryl cysteine. Specifically, the present invention provides enantioselective method for preparing S-aryl cysteine starting from cystine, cysteine or serine amino acid. The methods of the present invention provides S-aryl cysteine in enantiomeric excess of greater than about 96%.