Asymmetric inverse electron-demand 1,3-dipolar cycloaddition of ynolates with chiral nitrones produced 5-isoxazolidinones with good diastereoselectivity. These products were easily converted into optically pure β-amino acids and chiral γ-butyrolactones.
Reaction between <i>N</i>-Alkylhydroxylamines and Chiral Enoate Esters: More Experimental Evidence for a Cycloaddition-like Process, a Rationale Based on DFT Theoretical Calculations, and Stereoselective Synthesis of New Enantiopure β-Amino Acids
作者:Albertina G. Moglioni、Elena Muray、José A. Castillo、Ángel Álvarez-Larena、Graciela Y. Moltrasio、Vicenç Branchadell、Rosa M. Ortuño
DOI:10.1021/jo0159082
日期:2002.4.1
for short reaction times. These compounds evolve to the corresponding isoxazolidinones on standing at room temperature or under acid catalysis. The high pi-facial diastereoselection has been rationalized on the basis of steric effects induced by the dioxolane ring for D-glyceraldehyde derivatives or by the cyclobutane gem-dimethyl substitution for esters prepared from (-)-verbenone. As an application