Abstract: | Carbonyl 2 + 2 photoaddition occurs selectively to the alkene moiety of 3-(4-methyl-3-pentenoxy)pyridine. Photolysis of alkene containing pyridines in acetophenone gives rise to an oxetane which is obtained with extremely high diastereoselectivity as shown by analysis of the major 2 + 2 photoproduct. A second photoproduct, 2,3-dihydroxy-2,3-diphenylbutane, is obtained as a result of acetophenone coupling. |