Ring-opening of some radicals containing the cyclopropylmethyl system
- 1 January 1980
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in Journal of the Chemical Society, Perkin Transactions 2
- No. 10,p. 1473-1482
- https://doi.org/10.1039/p29800001473
Abstract
Mono- and bi-cyclic radicals containing the cyclopropylmethyl system are readily generated by interaction of the appropriate halides with triphenyl- or tributyl-stannane. Each radical studied underwent ring-opening by fission of the more substituted βγ-bond. In the case of the secondary radical (12b) the new double bond was formed preferentially in the trans-configuration. Rate constants, which cannot be determined with high accuracy by this method, lie in the range 1 × 107–3 × 108 s–1 at 25 °C. When generated by the flow method in the e.s.r. cavity α-hydroxycyclopropylmethyl radicals undergo β-fission followed by 1,5-hydrogen atom transfer to afford enoxyl radicals. The latter reaction occurs more slowly in water than in non-polar solvents. The rigid hydroxynortricyclyl radical (43) undergoes preferential fission of the less substituted βγ-bond, possibly because of the dipolar nature of the transition state.This publication has 0 references indexed in Scilit: