Synthesis of 4-alkoxy and 3-nitro substituted isoxazolidines by catalyzed 1,3-dipolar cycloaddition reactions of nitrones with vinyl ethers and nitro alkenes

Article abstract of DOI:10.1002/prac.19973390175

1,3-Dipolar cycloadditions of the C-phenyl-N-alkylnitrones 1,3 and the C,N-diphenylnitrone (2) with vinyl ethers 5,6 are strongly catalyzed by chiral oxazaborolidines derived from N-arylsulfonyl substituted L-α-amino acids valine and tert-butyl leucine an