Chemoenzymic synthesis of the C-13 side chain of taxol: optically active 3-hydroxy-4-phenyl .beta.-lactam derivatives
摘要:
Enantiomerically-pure 3-hydroxy-4-phenyl beta-lactam derivatives have been successfully prepared via enantioselective hydrolyses and transesterifications of racemic esters and alcohols respectively catalyzed by bacterial lipases. These lipases also catalyzed highly enantioselective cleavage of the beta-lactam ring of (+/-)-10 to yield derivatives of (2R,3S)-phenylisoserine in high enantiomeric excess. The resolved enantiomers are important intermediates in the synthesis of the C-13 side chain of taxol.
The present invention is directed to a process for the preparation of β-lactams. Generally, an imine is cyclocondensed with a ketene acetal or enolate to form the β-lactam product in a “one pot” synthesis, this process is generally performed at a higher temperature than conventional processes.
Utilization of (18-Crown-6)-2,3,11,12-tetracarboxylic Acid as a Chiral NMR Solvating Agent for Diamines and β-Amino Acids
作者:Yolanda C. Rodriguez、Tayla M. Duarte、Zsolt Szakonyi、Enikő Forró、Ferenc Fülöp、Thomas J. Wenzel
DOI:10.1002/chir.22491
日期:2015.10
The compound (18‐crown‐6)‐2,3,11,12‐tetracarboxylic acid was evaluated as a chiral nuclear magnetic resonance (NMR) solvatingagent for a series of diamines and bicyclic β‐amino acids. The amine must be protonated for strong association with the crown ether. An advantage of (18‐crown‐6)‐2,3,11,12‐tetracarboxylic acid over many other crown ethers is that it undergoes a neutralization reaction with neutral
New Enzymatic Two-Step Cascade Reaction for the Preparation of a Key Intermediate for the Taxol Side-Chain
作者:Enikő Forró、Ferenc Fülöp
DOI:10.1002/ejoc.201000262
日期:——
Enzymatic strategies are reported for the synthesis of (2R,3S)-3-amino-2-hydroxy-3-phenylpropionic acid (ee > 98 %), a keyintermediate of the side-chain of Taxol®, by enzymatic hydrolysis in organic media. The newenzymaticcascadereaction, which took place through Candida antarctica lipase B-catalysed deacylation followed by lactam ring-opening of racemic cis-3-acetoxy-4-phenylazetidin-2-one with
Process for the preparation of a taxol intermediate comprising contacting an alcohol with an oxazinone having the formula: ##STR1## wherein R.sub.1 is aryl, heteroaryl, alkyl, alkenyl, alkynyl or OR.sub.7 wherein R.sub.7 is alkyl, alkenyl, alkynyl, aryl or heteroaryl; R.sub.2 and R.sub.5 are independently selected from hydrogen, alkyl alkenyl, alkynyl, aryl, heteroaryl, and OR.sub.8 wherein R.sub.8 is alkyl, alkenyl, alkynyl, aryl, heteroaryl, or hydroxyl protecting group; and R.sub.3 and R.sub.6 are independently selected from hydrogen, alkyl, alkenyl, alkynyl, aryl and heteroaryl.
Method for preparation of taxol using .beta.-lactam
申请人:Florida State University
公开号:US05175315A1
公开(公告)日:1992-12-29
A .beta.-lactam of the formula: ##STR1## wherein R.sub.1 is aryl, substituted aryl, alkyl, alkenyl, or alkynyl; R.sub.2 is hydrogen, alkyl, acyl, acetal, ethoxyethyl, or other hydroxyl protecting group; and R.sub.3 is aryl, substituted aryl, alkyl, alkenyl, or alkynyl; and process for the preparation of taxol comprising contacting said .beta.-lactam and an alcohol in the presence of an activating agent to provide a taxol intermediate, and converting the intermediate to taxol.