Methyleneketenes and methylenecarbenes. VI. Pyrolytic generation of acyloxycarbenes and their rearrangement to 1,2-diketones

Abstract

Thermal fragmentation of 5-acyloxy-1,3-dioxan-4,6-diones (4) or thermal α-elimination of benzoic acid from the benzoyloxylactones (14) and (15) leads to 1,2-diketones in high yield. It is proposed that these 1,2-diketones are products of the rearrangement of transient intermediates which are formulated as acyloxycarbenes.