Isoxazoline derivatives. Part VII. Behaviour of 5-acyl-Δ2-isoxazolines with bases. Ring–chain tautomerism of 5-hydroxy-Δ2-pyrrolin-4-ones
Abstract
Reaction with bases of 5-acyl-Δ2-isoxazolines gave nitriles, α-diketones, and Δ2-pyrrolin-4-ones. N.m.r. studies revealed that Δ2-pyrrolin-4-ones exhibited ring–chain tautomerism under a large range of solvent polarities. Possible mechanisms for this base-promoted reaction are suggested. N.m.r., i.r., and u.v. data are reported.