Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

3-Hydroxybutyric acid asymmetric synthesis

Asymmetric epoxidation of homoallylic alcohols. Sharpless asymmetric epoxidation of primary homoallylic alcohols with l-( + )-diethyl tartrate proceeds with only moderate enantiomeric selectivity (23-55% ee) and opposite to that observed with allylic alcohols. Unfortunately, operation at low temperatures to improve the enantiomeric excess also retards the rate drastically. Even so, this epoxidation provides a useful synthesis of (-l-)--y-amino-P(R)-hydroxybutyric acid (1). [Pg.90]

Asymmetric synthesis of fi-lactams The [2+2]cycloaddition of benzyloxyketencs and imincs 2 derived from (R)-l results in. l -riy-disubstituted /8-lactams (3), which can be converted to optically active 3-amino-2-hydroxybutyric acids (5). [Pg.188]

Rossiter BE, Shaipless KB. Asymmetric epoxidation of homoallylic alcohols. Synthesis of (—)-7-amino-p-(i )-hydroxybutyric acid (GABOB). J. Org. Chem. 1984 49(20) 3707-3711. [Pg.1086]

A comprehensive review of asymmetric hydrogenation, mainly 2-oxo-carboxylic acids and their esters, over heterogeneous catalysts of Pt-alumina modified with alkaloids was presented in Chapter 5 of this book. Here some practical aspects of these catal5i ic systems will be considered. Thus, ethyl (i )-4-phenyl-2-hydroxybutyrate is an important intermediate for the synthesis of the angiotensin-converting enzyme inhibitor Benazepril (Scheme 7.20.) and other carboxyalkyl dipeptides like Enalapril (Scheme 7.21.)... [Pg.284]

In the field of antibiotics, some intermediates for carbapenems have been synthesized from ethyl (S)-P-hydroxybutyrate (Fig. 5) [34-36]. In these syntheses, the construction of the hydroxy etiiyl moieties of the target molecules is accompanied by inversion of the configurations at the asymmetrical centers of the starting materials. Ethyl (5)-3-hydroxy-butyrate has also been employed for the synthesis of grahamimycin A1 (unnatural form) [38], colletodiol [39], and pseudomonic acid C [40], which are all other antibiotics. [Pg.359]


See other pages where 3-Hydroxybutyric acid asymmetric synthesis is mentioned: [Pg.374]    [Pg.6]    [Pg.584]    [Pg.673]   
See also in sourсe #XX -- [ Pg.6 , Pg.315 ]




SEARCH



3- Hydroxybutyric acid

3- Hydroxybutyric acid/3-Hydroxybutyrate

3-hydroxybutyrate

4- -4-hydroxybutyric

© 2024 chempedia.info