10.1021/jo00141a046
The research focuses on the exploration of asymmetric 1,3-dipolar cycloadditions, a field that has been less studied compared to asymmetric Diels-Alder reactions. The purpose of the study was to investigate the high chiral induction potential of a chiral vinyl sulfoxide, (R)-(+)-p-tolyl vinyl sulfoxide, in its reaction with typical acyclic nitrones. The researchers observed high chiral induction in these reactions, which suggests the potential use of this sulfoxide as a chiral inducing agent in cycloadditions. The study concluded with the successful synthesis and characterization of various isoxazolidines and their subsequent transformations, demonstrating the effectiveness of the chiral sulfoxide in inducing asymmetry. Key chemicals used in the process included (R)-(+)-p-tolyl vinyl sulfoxide, C,N-diphenylnitrone, and various reagents for the transformations and analyses, such as LiAlH4 for reduction, CH3-O and NaB3H3CN for N-methylation, and Eu(hfcI3) as a chiral NMR shift reagent for determining enantiomeric excess.