Amide-Directed Catalytic Asymmetric Hydroboration of Trisubstituted Alkenes
作者:Sean M. Smith、James M. Takacs
DOI:10.1021/ja908257x
日期:2010.2.17
rhodium-catalyzed reaction is stereospecific. In addition, simple TADDOL-derived phenyl monophosphite ligands in combination with Rh(nbd)(2)BF(4) afford highly enantioselective catalysts (seven examples, 91-98% ee). These catalysts provide an alternative methodology to prepare Felkin or anti-Felkin acetate-aldol products and related derivatives that are obtainable from the intermediate chiral organoboranes
The Synthesis of the High-Potency Sweetener, NC-00637. Part 3: The Glutamyl Moiety and Coupling Reactions
作者:David J. Ager、Scott Babler、Robert A. Erickson、Diane E. Froen、Jeannine Kittleson、David P. Pantaleone、Indra Prakash、Ben Zhi
DOI:10.1021/op0341115
日期:2004.1.1
The synthesis of the high-potency sweetener, NC-00637 (1), required selective preparation of the γ-protected glutamicacid. Coupling of the three components could be performed in any order, but the final route involved N-acylation of the protected l-glutamic acid with the acidchloride derived from (S)-2-methylhexanoic acid. Activation of the α-carboxyl group allowed condensation with 5-amino-2-cyanopyridine
Sweetening agent derived from L-aspartic or L-glutamic acid
申请人:——
公开号:US05196540A1
公开(公告)日:1993-03-23
The present invention relates to a novel sweetening agent and to its method of preparation. This novel sweetening agent is a 2-substituted acyl derivative of L-aspartic or L-glutamic acid and has the general formula ##STR1## R being an acyl group of the formula ##STR2## and R' being a group of the formula ##STR3## R.sub.1, R.sub.2, R.sub.3, X, Y and Z being variously defined. This novel sweetening agent is essentially characterized by a high sweetening potency and a high stability compatible with the conditions of industrial use, and is applied especially for sweetening soft drinks.