One-pot efficient synthesis of N α-urethane-protected β- and γ-amino acids
摘要:
1-[(4-Methylphenyl)oxy]pyrrolidine-2,5-dione and 1-[(4-methylphenyl)oxy]piperidine-2,6-dione react in a Lossen-type reaction with primary alcohols in the presence of triethylamine to furnish corresponding N (alpha)-urethane-protected beta-alanine and gamma-aminopropionic acid (GABA), respectively, with excellent yields and purities, in an essentially "one-pot" procedure.
Molecular Transporters Based On Alditol Or Inositol And Processes For The Preparation Thereof
申请人:CHUNG Sung-Kee
公开号:US20080039421A1
公开(公告)日:2008-02-14
The inventive molecular transporter compound shows significantly high permeability through a biological membrane such as plasma membrane, nuclear membrane and blood-brain barrier, and accordingly, it can be effectively used in delivering various biologically active molecules, such as doxorubicin and paclitaxel to target cells.
The reaction of N-(3-phenylpropionyloxy)phthalimide (1a) and N-tosyloxy (5a,b) derivatives with nucleophiles was examined and found to give the products via Lossen-type rearrangement. In order to obtain the scope of this reaction mechanism, further studies the reaction of several N-sulfonyloxyimide derivatives with various nucleophiles under similar conditions were carried out and found to afford the
Enzymatic Removal of Carboxyl Protecting Groups. III. Fast Removal of Allyl and Chloroethyl Esters by <i>Bacillus subtilis</i> Esterase (BS2)
作者:Irene Fotakopoulou、Efrosini Barbayianni、Violetta Constantinou-Kokotou、Uwe T. Bornscheuer、George Kokotos
DOI:10.1021/jo061871f
日期:2007.2.1
esterase from Bacillus subtilis (BS2) allows the fast and selective removal of allyl, 2-chloroethyl, and 2,2,2-chloroethyl esters under mild conditions in high yields. In addition, BS2 easily hydrolyzes phenacyl esters, while the hydrolysis of sterically hindered diphenylmethyl esters is slow, requiring longer reaction time and higher enzyme/substrate ratio.
This paper reports the reaction of N-(phthalimidoyloxy)-3-phenylpropionate (2a) and -tosylate (6) with benzyl alcohol as a nucleophile to afford the products via Lossen-type rearrangement. To study the scope of this reaction mechanism, we also studied the reaction of several N-sulfonyloxyimide derivatives with benzyl alcohol under similar conditions and found that the same types of products were obtained
Molecular Transporters Based on Sugar and Its Analogues and Processes For the Preparation Thereof
申请人:Chung Sung-Kee
公开号:US20080249296A1
公开(公告)日:2008-10-09
The inventive molecular transporter compound shows significantly high permeability through a biological membrane such as a plasma membrane, nuclear membrane and blood-brain barrier, and accordingly, can be effectively used in delivering various biologically active molecules.