The photochemistry of estr-4-en-3-ones la, b is solvent dependent, yielding estr-5-en-3-ones 2 in ethyl acetate or 5a-estran-3-ones 3 in alcoholic solvents. Further irradiation of 5a-estran- 3-ones 3 in alcoholic solvent yields the 2, 3-and 3, 4-seco-5a-estrane 3-esters 4 and 5 and the 2, 3-secoestr-l-en-3-al (6). Photolysis of estra-4, 9-dien-3-one 7 yields the photodimer 8 whereas the estra-4, 9, 11-trien-3-one 9 yielded polymer.
![(8R,9S,10R,13R,14S,17R)-13-ethyl-17-ethynyl-17-hydroxy-1,2,4,7,8,9,10,11,12,14,15,16-dodecahydrocyclopenta[a]phenanthren-3-one结构式](https://image.chemsrc.com/caspic/115/100021-05-4.png)