N-Tritylprolinal: An Efficient Building Block for the Stereoselective Synthesis of Proline-Derived Amino Alcohols
摘要:
N-Tritylprolinal (prepared in four steps from L-proline) shows a very high Felkin diastereoselectivity in its reaction with various nucleophiles, leading to a straightforward and highly stereoselective access to syn-proline-derived amino alcohols.
Asymmetric Synthesis of (α<i>R</i>)-Polyfluoroalkylated Prolinols Based on the Perfluoroalkyl-Induced Highly Stereoselective Reduction of Perfluoroalkyl <i>N</i>-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-carboxylate in yields of 73−97% with excellent diastereoselectivities (up to >98% de), compared with the reduction of nonfluorinated (S)-tert-butyl