Irradiation of enol acetates with a low-pressure mercury lamp was studied. Irradiation of isopropenyl acetate (1) and cyclohexenyl acetate (3) resulted in an acetyl rearrangement and yielded, respectively, acetylacetone (2) and α-acetylcyclohexanone (4). Similarly, steroidal enol acetates 9, 11, and 13 gave corresponding ketones 10, 12, and 14. In all these irradiations considerable amounts of the starting materials were isolated. Enol acetate with a fully substituted double bond (S) gave, in addition to 2-acetyl-2-methylcyclohexanone (7), 2-methylcyclo-hexanone (6) and its dimer 8. An analogous steroidal enol acetate 15 resulted mainly in the dimer 21 and also in the ketones 16, 17, and 18. It was found that acetyl migration occurs by an intramolecular process, suggesting a cage mechanism. The stereochemistry of this photochemical acetyl rearrangement is also discussed.
|Number of pages||6|
|Journal||Journal of the American Chemical Society|
|State||Published - 1 Dec 1964|
ASJC Scopus subject areas
- Chemistry (all)
- Colloid and Surface Chemistry