[3+2] Route to Quaternary Oxaprolinol Derivatives as Masked Precursors of Disubstituted β 3 ,β 3 -Amino Aldehyde
Résumé
Isoxazolidines displaying a quaternary stereocenter were formed starting from functional cyclic ketonitrones through a highly stereocontrolled 1,3‐dipolar cycloaddition. Chemoselective reductive chiral auxiliary removal gives quaternary oxaprolinol derivatives, which were further transformed into dipeptides terminated directly with an aldehyde function.