The vinylfluoro group as an acetonyl cation equivalent: stereoselective synthesis of 6-substituted 4-hydroxy pipecolic acid derivatives

An unprecedented cascade of reactions is described after acid-catalyzed hydrolysis of tert-butyl (2S,5S)-2-tert-butyl-5-(2-fluoroallyl)-3-methyl-4-oxoimidazolidine-1-carboxylate that has led to pipecolic acid derivatives. The pipecolic acid is used for preparing (2R,4R,6S)-6-tert-butyl-4-hydroxypiperidine-2-carboxylic acid.