Synthesis of 1,3-dioxin-4-ones and their use in synthesis. Part XXII. A novel synthetic method for tetronic acids from 1,3-dioxin-4-ones via intra- or intermolecular ketene trapping.

Abstract

Novel synthetic routes to tetronic acid and its derivatives from 6-substituted 1, 3-dioxin-4-ones through cycloreversion to acylketenes followed by either intra- or intermolecular ketene trapping by a hydroxy function is described. While tetronic acid and its 5-substituted derivatives were synthesized directly from 6-(x-hydroxyalky)-1, 3-dioxin-4-ones by intramolecular trapping, 3-acyltetronic acids were prepared by Dieckmann reaction of the β-keto esters obtained from the 6-substituted dioxinones and an approptiate α-hydroxy ester by intermolecdular trapping.