Stereoselective Synthesis of Enantiomerically Pure Piperidine Derivatives byN-Galactosylation of Pyridones
作者:Ellen Klegraf、Markus Follmann、Dieter Schollmeyer、Horst Kunz
DOI:10.1002/ejoc.200400169
日期:2004.8
Stereoselective desymmetrization of 4-pyridone has been achieved through selective N-galactosylation, activation of the N-(galactosyl)pyridone by O-silylation and immediate addition of Grignard compounds. Chiral piperidine derivatives, e.g. (S)-(+)-coniine and (5S,9S)-(+)-indolozidine 167B, were synthesised in enantiomerically pure form using these highly regio- and stereoselective reactions. After
4-吡啶酮的立体选择性去对称化已经通过选择性 N-半乳糖基化、通过 O-甲硅烷基化激活 N-(半乳糖基)吡啶酮和立即添加格氏化合物来实现。手性哌啶衍生物,例如 (S)-(+)-coniine 和 (5S,9S)-(+)-indolozidine 167B,使用这些高度区域和立体选择性反应以对映体纯形式合成。在 2-吡啶酮的 N-半乳糖基化和 N-半乳糖基-2-吡啶酮的 O-甲硅烷基化后,格氏化合物的添加以高 1,4-区域选择性和完全非对映选择性进行,以提供 4-取代的 5,6-脱氢- 2-哌啶酮。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)