Umlagerungen von Heterocyclen, VI Über die Umsetzung von reaktiven Malonestera mit Benzalaceton und Cinnamoylaceton / Rearrangement Reactions of Heterocycles, VI The Reaction of Reactive Malonates with Benzalacetone and Cinnamoylaceton

Abstract

Trichlorophenylmalonates (1) react with benzalacetone (2) to give 4-hydroxy-6-styryl- 2-pyrones (3) and the isomeric 2:1 condensation products 4 and 5 which are interconvertable. Cinnamoylacetone (8) reacts at different temperatures to three isomeric pyrones (9, 10, and 11). Thermal rearrangement of 9 yields 10 and the latter compound at highter temperatures 11.