AN IMPROVED PROCEDURE FOR THE PREPARATION OF 2-ISOXAZOLINES

Article abstract of DOI:10.1016/S0040-4020(01)91313-4

Aldoximes were converted in high yields by N-Chlorosuccinimide into hydroxamic acid chlorides, and corresponding nitrile oxides generated by addition of triethylamine at 40-50 deg C underwent 1,3-dipolar addition to alkenes, giving 2-isoxazolines.The whole procedure could be performed as a one-pot reaction.Oximes with other functions, sensitive to free chlorine could be converted selectively into hydroxamic acid chlorides by this procedure.Isopropylidene glyceraldoxime was added to acrolein diethylacetal thus affording an entrance to carbohydrate synthesis but the stereospecificity of the reaction is low. 2:3, 5:6-Di-O-isopropylidene-D- mannose oxime was converted to the N-hydroximinolactone by treatment with NCS and base.