Highly lk-Selective Asymmetric Nitrile Oxide Cycloadditions to a C2-Symmetric 1,3-Diacryloyl-2,2-dimethylimidazolidine and 4-Chiral 3-Acryloyl-2,2-dialkyloxazolidines

Article abstract of DOI:10.1016/S0040-4020(01)89440-0

1,3-Dipolar cycloadditions of benzonitrile oxide to the acrylamides derived from a C2-symmetric 2,2-dimethylimidazolidine and 4-chiral 2,2-dialkyloxazolidines show high lk-diasteroselectivities.Easy separation of the major lk-isomers from the minor ul-diastereomers is followed by reductive removal of the chiral auxiliaries to produce optically pure 2-isoxazoline-5-methanols.Absolute diastereoselectivities were recorded in the nitrile oxide cycloadditions of 3-acryloyl-2,2-dialkyl-4-(diphenylmethyl)oxazolidines at 0 deg C.