Asymmetric synthesis. Practical production of D and L threonine. Dynamic kinetic resolution in rhodium and ruthenium catalyzed hydrogenation of 2-acylamino-3-oxobutyrates.
摘要:
Enantioselective syntheses of D and L threonine are described. Racemic methyl and ethyl 2-acylamino-3-oxobutyrate 1 were synthesized from the corresponding acetoacetates 6 and then hydrogenated stereoselectively via dynamic kinetic resolution with various chiral P * P Rh (I) 8 and Ru (II) 10 catalysts to give syn optically active alcohols which could be converted by hydrolysis and treatment with propylene oxide into threonine. The best results were obtained using (-) CHIRAPHOS Ru and (+) BINAP Ru as catalysts, in the hydrogenation step leading respectively to D threonine (ee: 99 %) and L threonine (ee: 94 %) in 26-34 % overall yields.
This application discloses a composition comprising a malodor compound and an anti-odor ingredient effective for reducing the presence or production of malodor. The composition may be topically applied to a subject and is useful for cosmetic conditions, pharmaceutical indications, or other objectives.
[EN] ANTI-ODOR COMPOSITIONS AND THERAPEUTIC USE<br/>[FR] COMPOSITIONS ANTI-ODEURS ET UTILISATION THERAPEUTIQUE ASSOCIEE
申请人:YU RUEY J
公开号:WO2006119283A2
公开(公告)日:2006-11-09
[EN] This application discloses a composition comprising a malodor compound and an anti-odor ingredient effective for reducing the presence or production of malodor. The composition may be topically applied to a subject and is useful for cosmetic conditions, pharmaceutical indications, or other objectives. [FR] L'invention concerne une composition contenant un composé malodorant et un ingrédient anti-odeurs permettant de réduire la présence ou la fabrication de mauvaises odeurs. Cette composition peut être topiquement appliquée sur un sujet et est utile dans le domaine cosmétique, pharmaceutique ou dans d'autres domaines.
Asymmetric synthesis. Practical production of D and L threonine. Dynamic kinetic resolution in rhodium and ruthenium catalyzed hydrogenation of 2-acylamino-3-oxobutyrates.
Enantioselective syntheses of D and L threonine are described. Racemic methyl and ethyl 2-acylamino-3-oxobutyrate 1 were synthesized from the corresponding acetoacetates 6 and then hydrogenated stereoselectively via dynamic kinetic resolution with various chiral P * P Rh (I) 8 and Ru (II) 10 catalysts to give syn optically active alcohols which could be converted by hydrolysis and treatment with propylene oxide into threonine. The best results were obtained using (-) CHIRAPHOS Ru and (+) BINAP Ru as catalysts, in the hydrogenation step leading respectively to D threonine (ee: 99 %) and L threonine (ee: 94 %) in 26-34 % overall yields.