Asymmetric synthesis of (αR)-polyfluoroalkylated prolinols based on the perfluoroalkyl-induced highly stereoselective reduction of perfluoroalkyl N-Boc-pyrrolidyl ketones

Reduction of the obtained chiral (S)-tert-butyl 2-(perfluoroalkanoyl)pyrrolidine-1-carboxylate with sodium borohydride or lithium aluminum hydride proceeded smoothly to give the corresponding (S)-tert-butyl 2-((R)-perfluoro-1-hydroxyalkyl)pyrrolidine-1-carboxyl ate in yields of 73-97% with excellent diastereoselectivities (up to >98% de), compared with the reduction of nonfluorinated (S)-tert-butyl 2-pentanoylpyrrolidine-1-carboxylate.