The Vinylfluoro Group as an Acetonyl Cation Equivalent: Stereoselective Synthesis of 6-Substituted 4-Hydroxy Pipecolic Acid Derivatives
摘要:
An unprecedented cascade of reactions after acid-catalyzed hydrolysis of tert-butyl (2S,5S)-2-tert-butyl-5-(2-fluoroallyl)-3-methyl-4-oxoimidazolidine-1-carboxylate 3a leading to pipecolic acid derivative 5 is presented. The vinylfluoro group is shown to be all acetonyl cation equivalent under acidic conditions. Interestingly, vinylchloro and vinylbromo groups do not show Such transformation under the same conditions. The pipecolic acid derivative 5 produced in this way is further used to synthesize (2R,4R,6S)-6-tert-butyl-4-hydroxypiperidine2-carboxylic acid 9.
The Vinylfluoro Group as an Acetonyl Cation Equivalent: Stereoselective Synthesis of 6-Substituted 4-Hydroxy Pipecolic Acid Derivatives
作者:Nirupam Purkayastha、Deepak M. Shendage、Roland Fröhlich、Günter Haufe
DOI:10.1021/jo901872a
日期:2010.1.1
An unprecedented cascade of reactions after acid-catalyzed hydrolysis of tert-butyl (2S,5S)-2-tert-butyl-5-(2-fluoroallyl)-3-methyl-4-oxoimidazolidine-1-carboxylate 3a leading to pipecolic acid derivative 5 is presented. The vinylfluoro group is shown to be all acetonyl cation equivalent under acidic conditions. Interestingly, vinylchloro and vinylbromo groups do not show Such transformation under the same conditions. The pipecolic acid derivative 5 produced in this way is further used to synthesize (2R,4R,6S)-6-tert-butyl-4-hydroxypiperidine2-carboxylic acid 9.