METHOD FOR PRODUCING OPTICALLY ACTIVE 2-HYDROXY ESTER AND NOVEL INTERMEDIATE COMPOUND
申请人:Shiina Isamu
公开号:US20110319650A1
公开(公告)日:2011-12-29
Disclosed is a method for producing an optically active 2-hydroxy ester, comprising selectively esterifying one enantiomer of a racemic 2-hydroxy ester in a solvent containing a catalyst such as tetramisole or benzotetramisole, and a carboxylic acid anhydride, or a carboxylic acid anhydride and a carboxylic acid. In particular, in the case where the solvent contains a carboxylic acid anhydride, but does not contain a carboxylic acid, as the carboxylic acid anhydride, a carboxylic acid anhydride containing a tertiary or quaternary carbon atom in the a-position is used. On the other hand, in the case where the solvent contains a carboxylic acid anhydride and a carboxylic acid, as the carboxylic acid, a carboxylic acid containing a tertiary or quaternary carbon atom in the a-position is used.
A convenient method for the kinetic resolution of racemic 2-hydroxyalkanoates using diphenylacetic anhydride (DPHAA) and a chiral acyl-transfer catalyst
作者:Kenya Nakata、Akihiro Sekiguchi、Isamu Shiina
DOI:10.1016/j.tetasy.2011.08.018
日期:2011.9
Diphenylacetic anhydride (DPHAA) was found to be a useful reagent for the kinetic resolution of racemic 2-hydroxyalkanoates in the presence of a catalytic amount of (R)-benzotetramisole ((R)-BTM). The combined use of DPHAA and (R)-BTM effectively produced a variety of the optically active 2-hydroxyalkanoates and the corresponding 2-acyloxyalkanoates from racemic 2-hydroxyalkanoates (s-values = 42-177). A fairly broad substrate scope was demonstrated by this novel chiral induction system. We also revealed that the use of only 0.3 equiv of DPHAA is enough to provide the optically active 2-acyloxyalkanoates in good yields and with excellent ee's by the added use of 0.3 equiv of pivalic anhydride for the kinetic resolution of the racemic 2-hydroxyalkanoates. (C) 2011 Elsevier Ltd. All rights reserved.
A Compact Chemical Miniature of a Holoenzyme, Coenzyme NADH Linked Dehydrogenase. Design and Synthesis of Bridged NADH Models and Their Highly Enantioselective Reduction<sup>1</sup>
作者:Nobuhiro Kanomata、Tadashi Nakata
DOI:10.1021/ja992990y
日期:2000.5.1
pyridine-formation reaction of formyl-substituted (vinylimino)phosphorane 4 with methyl propiolate. The bridged NADH models 10a−c effected excellent biomimetic reduction at various temperatures in the presence of magnesium ion to achieve both the enantioselective and stereospecific reduction of the pyruvate analogues 12u−z into chiral lactate analogues 13u−z with 88−99% ee. The high enantioselectivity was almost