Synthesis of pyridine oxides and isoxazolines from 4-(2-oxoalkylidene)-pyrans
Abstract
The reaction of 2,6-disubstituted and 2,5,6-trisubstituted 4-(2-oxoalkylidene)pyrans with hydroxylamine yields oximes of 4-(2-oxoalkyl)pyridine N-oxides or substituted Δ2-isoxazolines, or a mixture thereof. The factors influencing the competition between the formation of these two types of product are discussed.