128500-08-3Relevant academic research and scientific papers
Photoreactions of 4-(tribromomethyl)-4-methyl-2,5-cyclohexadienone and its derivatives with amines: Radical cyclization and ring expansion reactions promoted through photoinduced electron transfer processes
Hasegawa, Eietsu,Tamura, Yukinobu,Suzuki, Kimiko,Yoneoka, Akira,Suzuki, Toshio
, p. 8780 - 8785 (1999)
Photoreactions of 4-(tribromomethyl)-4-methyl-2,5-cyclohexadienone (1) and its derivatives with amines were studied. Irradiation of 1 with amine produced 4-bromo-5-methyltropone (2) along with 4-(dibromomethyl)-4-methyl- 2,5-cyclohexadienone (3). The effects of solvent, added water, and the structural variation in amine on the product ratio were explored. Isolation of the amine-derived products revealed that oxidative dealkylation of amine proceeded during the photoreaction. On the basis of the results obtained, a reaction mechanism involving fragmentation of the dienone anion-radical and amine cation-radical pair is proposed. Photoreactions of dienone 4 with amine produced the tropones 6 and 7, whereas tropone 9 was produced from 8. Trialkyltin radical-induced reductions of dienones 1 and 4 with tri-n- butyltin hydride demonstrated common features with the photoreactions. It was also found that irradiation of dienone 3 with amine produced 4-methyltropone (10).
