Reaction of 2-Isoxazolines with Organolithiums in the Presence of Boron Trifluoride

Article abstract of DOI:10.1246/bcsj.66.2730

In the presence of boron trifluoride,3,4,5-tri-, 3,5,5-tri and 3,5-disubstituted 2-isoxazolines underwent nucleophilic addition of alkyl- and aryllithiums to give 3,3,4,5-, 3,3,5,5-, and 3,3,5-substituted isoxazolidines in moderate to good yields.On the other hand, in the case of 3,4,5,5-tetrasubstituted isoxazolines, the addition did not proceed at all but proton abstraction took place to afford a "ate" complex of isoxazoline anions, formation of which was confirmed by deuteration and the aldol reaction with benzaldehyde.