UV irradiation of arylidene-β-ionones in the presence of dioxygen: regioselective formation of stable endoperoxides

✍ Scribed by Rajinder Singh; M.P.S. Ishar

• Book ID: 104253026
• Publisher: Elsevier Science
• Year: 2003
• Tongue: French
• Weight: 124 KB
• Volume: 44
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(03)00086-8

✦ Synopsis

UV irradiation of (E,E)-arylidene-b-ionones 1 leads to photoisomerization resulting in (Z,E) arylidene-b-ionones 2, which undergo electrocyclization to 1,7,7-trimethyl-3-(E-2%-arylethenyl)-2-oxabicyclo[4.4.0]deca-3,5-dienes 3, and the latter in the excited state add regioselectively, involving only the electron-rich endocyclic diene, to molecular oxygen affording highly stable endoperoxides 6.