HIGHLY LK-SELECTIVE ASYMMETRIC NITRILE OXIDE CYCLOADDITIONS TO A C-2-SYMMETRICAL 1,3-DIACRYLOYL-2,2-DIMETHYLIMIDAZOLIDINE AND 4-CHIRAL 3-ACRYLOYL-2,2-DIALKYLOXAZOLIDINES

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-diastereoselectivities. 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-degrees-C.