1,2-Diarylcyclopropane, photooxygenation

Independently and concomitantly, similar conclusions on the electron-transfer photooxygenations of several substituted 1,2-diarylcyclopropanes, 79a-d, affording the corresponding 1,2-dioxolanes, 80a-d, in high yields as well as high... 

The photooxygenation of 3-alkyl-1,2-diarylcyclopropanes occurs with a high stereoselectivity in the presence of Mg(C104)2 (Scheme 56) [158], Shim reported the DCA-sensitized photooxygenation of vinyl cyclopropanes in the presence of Mg ( 104)2 and biphenyl [159]. 

TCNE takes place (Scheme 57). Tomioka reported the (3 + 2) photocycloaddition between 1,1,2-triarylcyclopropanes and vinyl ethers in the presence of p-DCB [162]. Mizuno and Otsuji reported the (4 -l- 2) photocycloaddition between 1,2-diarylcyclopropanes and DCA [23]. The 1,4-radical cation produced as an intermediate of the Cope rearrangement of 1,5-dienes via photoinduced electron transfer can be trapped by molecular dioxygen, giving bicyclic dioxanes (Scheme 58) [163]. This photooxygenation takes place in a stereospecific manner. 

Mizuno, K., Nire, K., Sugita, H., and Maeda, H., A novel cis-trans photoisomerization of vinylidenecyclopropanes via an electron transfer chain process. Tetrahedron Lett., 42, 2689, 2001. Mizuno, K., Ichinose, N., and Otsuji, Y., cis-trans Photoisomerization and photooxygenation of 1,2-diarylcyclopropanes. Salt effects on the photoinduced electron transfer reactions, Chem. Lett., 455, 1985. 

---