Electron impact mass spectra of some dioximes ofo-diacyl benzenes
摘要:
AbstractThe electron impact mass spectra of the new synthesized dioximes of o‐diacyl benzenes (2) are reported. In addition to the molecular ion, characteristic peaks appear at values corresponding to the [M − OH] +, [M − NOH]+ and [M − NHOH]+ ions. No initial dehydration of the molecular ion has been observed.
Mechanism of the replacement of phenolic hydroxyl by carbonyl on lead tetraacetate treatment of o-hydroxyaryl ketone acylhydrazones
摘要:
A mechanistic study has been carried out on the reaction of acylhydrazones of omicron-hydroxyaryl ketones 6 with lead tetraacetate, which gives 1,2-diacylbenzenes 7 by a novel overall replacement of phenolic hydroxyl with an acyl group. Cross-over experiments demonstrate that the reaction is intramolecular. Oxygen-labeling evidence suggests that following formation of the 1,3,4-oxadiazoline 10, cyclization with loss of acetic acid leads to the tricyclic 1,3-dioxane 11. Elimination of nitrogen leads to an intermediate 12, which rearranges to the 1,2-diacylbenzene 7.