Studies on heterocyclic chemistry. Part II. 4-Alkylidene- and 4-arylidene-isoxazol-5-ones. Participation in and retrogression of the Michael adducts

Abstract

A product C₁₁H₁₄N₂O₄ obtained in the reaction of ethyl acetoacetate and hydroxylamine has been identified as (II), and evidence is presented that it was formed through 4-isopropylidene-3-methylisoxazol-5-one (III). A Michael reaction of 4-benzylidene-3-methylisoxazol-5-one (VII) is also recorded.