Interconversion of l-Phenyl-5-hexenyl, 2-Phenylcyclopentylmethyl, and 3-Phenylcyclohexyl Radicals

Journal of the American Chemical Society

Volumn 94, Issue 17, 1972, Pages 6064-6069

  Walling, Cheves ^a,b   Cioffari, Angela ^a  

^a Och Spine at New York Presbyterian Hospitals   (United States)

^b UNIVERSITY OF UTAH   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0343043242     PISSN: 00027863     EISSN: 15205126     Source Type: Journal    
DOI: 10.1021/ja00772a021     Document Type: Article

References (7)

1. C. Walling and A. Cioffari, J. Amer. Chem. Soc., 94, 6059 (1972).
2. C. Walling, J. H. Cooley, A. A. Ponaras, and E. J. Racah, J. Amer. Chem. Soc., 88, 5361 (1966).
3. Since this work was completed, reversibility of this system under conditions of longer radical lifetime has been reported: M. Julia, Accounts Chem. Res., 4, 386 (1971).
4. D. J. Carlsson and K. U. Ingold, J. Amer. Chem. Soc., 90, 7047 (1968), report the rate constanss for primary alkyl and cyclohexyl radicals with tributylstannane are the same within experimental error (1 × 10).
5. For discussion, cf. C. Walling, “Molecular Rearrangements,” P. de Mayo, Ed., Interscience, New York, N. Y., 1963. 1,2-Hydrogen and alkyl rearrangements in biradicals are well established.
6. 8 and charge-separated structures similar to (8) may also be invoked to account for facile rearrangements observed in diradicals: cf. C. Walling, H. P. Waits, J. Milovanovic, and C. G. Pappiaonnou, J. Amer. Chem. Soc., 92, 4927 (1970).
7. However, H. Pines, N. C. Sih, and D. B. Rosenfield, J. Org. Chem., 31, 2255 (1966), have reported B, C, D, and E as products when 6-phenyl-1-hexene is heated with peroxides at 85–150°. Here radical lives would be much longer than in our systems, and since product formation depends on R· + R″H → RH + R″ · reactions, there should be a strong selectivity for five-membered ring products derived from primary radicals.