Photoinduced transformations. Part 33. Mechanism of photoinduced rearrangement of a (22S,25S)-N-acetylveratr-13(17)-enin-11β-yl nitrite, a fused cyclopentyl nitrite, to a nitrone

Abstract

In order to define the pathway of photoinduced rearrangement of (22S,25S)-N-acetylveratr-13(17)-enine-3β,11β,-23β-triol 3,23-diacetate 11-nitrite (1) to the six-membered ring nitrone (2), studies were made of the results of irradiation with monochromatic light and the solvent dependence of the reaction; the assumed intermediates were isolated and their reactions investigated at both 77 K and room temperature, and quantum yields were measured. On the basis of the results, together with those of cross-over experiments with ¹⁵N-labelled species previously reported, pathways from the nitrite to the nitrone are discussed.