Photochemical transformations - XIII. The mechanism of the reaction of Δ3,5-cholestadiene1,2

✍ Scribed by William G. Dauben; Fred G. Willey

• Publisher: Elsevier Science
• Year: 1962
• Tongue: French
• Weight: 312 KB
• Volume: 3
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)70560-0

✦ Synopsis

OF THE FAIRLY extensive studies of the photochemistry of cisoid conjugated dienes have established that ultraviolet irradiation of such systems usually leads to formation of a new bond between carbon atoms 1 and 4 of the diene to yield a cyclobutene or, in the special case of some six-membered rings, to bond cleavage to form a hexatriene. 4 These two types of reactions are virtually impossible with a diene held in a transoid conformation, since to bond carbon atoms 1 and 4 would require introduction of excessive strain, and to open a ring appears ' For Paper XII, Chem. Sot. see W. G. Dauben and Fred G. Willey, J. Am. 8, 1497 (1962) .