Photochemistry of cyclopentadienone dimers

✍ Scribed by K.N. Houk; D.J. Northington

• Book ID: 104236390
• Publisher: Elsevier Science
• Year: 1972
• Tongue: French
• Weight: 172 KB
• Volume: 13
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)84307-0

✦ Synopsis

The photochemistry of several cyclopentadienone dimers, & has been reported recently. The excited singlet states of &and l&undergo cl,31 sigmatropic shifts to form & and 2&, while the triplet state of & forms the [2+21 cage isomer 3a.1'2 Recently, Fuchs reported a; R= R/= H b; R=H; R/= Ph c; R= Me; RI Ph that the photochemistry of & is anomalous since ft along with traces of &are produced upon photolysis of &,. Fuchs concluded that the dimer of 2,3-dimethyl-3,4-diphenylcyclopentadienone &, has the exo configuration2, contradicting an earlier conclusion of Warrener and co-workers. 3 Since &dissociates in solution, while ,&, and & are thermally stable,' we chose to investigate more closely the photochemistry of & and A.

In the course of these investigations, we have discovered that the photochemistry of cyclopentadienone dimers is extremely sensitive