78229-57-9Relevant academic research and scientific papers
Dispirocyclobutanes and Propellanes from 1,2-Bisenollactones
Kaup, Gerd,Schmitt, Dieter
, p. 1983 - 1990 (2007/10/02)
Electronically excited biphthalidylidene (1) and isocoumarino-isocoumarin (5) are trapped by electron-poor stilbenes and by 1,3-dienes to give the dispirocyclobutanes 3, 8, 9, 11, 12 and the heterocyclic propellanes 6 and 14, resp.The unusual tetraspirocyclobutane 4 is formed upon photodimerization of 1 as a by-product.The structures of the products have been established primarily by high-field 1H-NMR spectroscopy and in part by chemical transformations.
