Efficient synthesis of an imidazole-substituted δ-amino acid by the integration of chiral technologies

被引：13

作者：

Appleby, I

Boulton, LT

Cobley, CJ

Hill, C

Hughes, ML

de Koning, PD

Lennon, IC

Praquin, C

Ramsden, JA

Samuel, HJ

Willis, N

机构：

[1] Dowpharma Chirotech Technol Ltd, Cambridge CB4 0WG, England

[2] Pfizer Ltd, Pfizer Global Res & Dev, Chem Res & Dev, Sandwich CT13 9NJ, Kent, England

来源：

ORGANIC LETTERS | 2005年 / 7卷 / 10期

关键词：

D O I：

10.1021/ol0503081

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

[GRAPHICS] Two methods to produce (2S)-5-amino-2-(1-n-propyl-1H-imidazol-4-ylmethyl)-pentanoic acid were investigated. Diastereoisomeric salt resolution, using the quinidine salt, gave the desired intermediate in 98% ee and 33% yield. Asymmetric hydrogenation of various substrates gave high conversions, with up to 83% ee. Integration of these two approaches via asymmetric hydrogenation of a quinidine salt substrate followed by crystallization provided the desired intermediate in 94% ee and 76% yield.

引用

页码：1931 / 1934

页数：4

共 17 条

[1]

ALLERTON CMN, 2002, Patent No. 2002014285

[2] 2,2′,5,5′-tetramethyl-4,4′-bis(diphenylphoshino)-3,3′-bithiophene:: A new, very efficient, easily accessible, chiral biheteroaromatic ligand for homogeneous stereoselective catalysis [J].