M. Meléndez-Rodríguez, C. M. Cerda-García-Rojas, C. A. N. Catalán, P. Joseph-Nathan Mechanistic studies of the photochemical rearrangement of 1-oxolongipin-2-ene derivatives Tetrahedron, Volume 58, Issue 12, 18 March 2002, Pages 2331-2338. ISSNI: 0040-4020 DOI: http://dx.doi.org/10.1016/S0040-4020(02)00121-7
Ultraviolet irradiation of (4R,5S,7S,8R,9S,10R,11R)-7,8,9-triacetyloxy-1-oxolongipin-2-ene (2) afforded the vulgarone A 7 and the pingilonene 8 derivatives as the major products, which were formed by a [1,3]-shift, together with the minor secondary photoproducts 9 and 10. The phototransformation mechanism is discussed in terms of individual ultraviolet irradiation of 7 and 8 in combination with the monitoring reaction progress of 2 by 1H NMR measurements. The stereostructures of the new carbocyclic skeleta were geometry optimized using density functional calculations.