Photochemical additions of 1,3-dienes to benzene

✍ Scribed by N.C. Yang; Jacqueline Libman

• Publisher: Elsevier Science
• Year: 1973
• Tongue: French
• Weight: 223 KB
• Volume: 14
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)95956-8

✦ Synopsis

Photochemical additions of benzene to alkenes have been a subject of current interest, 1,2,3 but only preliminary investigations have been reported on the corresponding reactions with 1,3dienes.4 graft and Koltzenberg found that benzene reacted photochemically with 1,3-butadiene and isoprene to give complex mixtures of products even at very low conversions. Major portions of the isolable products may be derived from two primary photochemical processes, a 4Ks+klrs photocycloaddition to give a 3-trans Isomer of bicyclo[k.2.2]deca-3,7,9-triene (l), and 1,2-addition of the diene to the 1,3-positions of benzene to give tricyclo[3.3.0.02'S]oct-3-enes (2). Compound la (RzH) or lb (R=C 5

) either dimerized to give a 2:2 adduct or reacted with the diene to give 1:2 adducts and thus could not be isolated. On the other hand, benzene reacted with 2,3-dimethyl-l,j-