Allenyl-vinyl methane system

Tsuno, T., Sugiyama, K., The Photochemical Reactivity of the Allenyl Vinyl Methane System. Horspool, W.M., Lenci, F. (eds), CRC Handbook of Organic Photochemistry and Photobiology, 2nd edn, CRC Press LLC, Boca Raton, FL, 2004, Chapter 30, pp. 1 15. 

The Photochemical Reactivity of the Allenyl-Vinyl Methane System... 

The photoreactivities for the intramolecular [2 + 2] -cycloaddition of the allenyl-vinyl methane systems increase with an increase in the number of methyl donating groups linked to the allene.The results of PM3 MO calculations of the model chromophores 21-25 in the aUenyl-vinyl methane systems are shown in Figure 30.2. The HOMOs of 22 and 23 lie at the C1-C2 position, whose coefficients have the same values. On the other hand, the HOMO of 21 lies at the C2-C3 position, and the MO coefficient of C3 has a larger value than that of C2. In addition, the MO coefficient of the P-carbon of 24 or 25 is... 

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