The photochemistry of several bicycloalkyl and cyclopentyl phenyl ketones has been investigated. The quantitative and stereoselective photochemical syntheses of a tricyclo[3.2.1.03′6]octane and tricyclo[3.3.1.02′7]-nonane are described. a-Methyl substituents are found to increase greatly the ratio of photocyclization to photoelimination products and to affect the reactivity of the carbonyl excited state toward 7-hydrogen abstraction. The large variation in the rate constants for secondary 7-hydrogen abstraction (2.5 X 106 to 1 X 1010 sec-1) for the ketones studied is attributed primarily to conformational factors.
ASJC Scopus subject areas
- Colloid and Surface Chemistry