ORGN 322 |
Synthesis of radical precursors for the study of the cyclopropylcarbinyl radical ring opening reaction
| Ian J. Rosenstein and Henry P. Chicaiza. Department of Chemistry, Hamilton College, 198 College Hill Road, Clinton, NY 13323 |
The cyclopropylcarbinyl radical ring opening is the best known radical clock, with a precisely determined rate constant of 1x108 s-1 at 25 °C. This ring opening is postulated to go through a dipolar transition state. The dipolar transition state was proposed after studies which showed the formation of the less stable radical in reactions involving non-symmetric cyclopropanes. The goal of this project is to support or disprove the hypothesis of the dipolar transition state through quantitative data. To do so we will set up competitive ring openings between cyclopropanes functionalized with substituted and unsubstituted aromatic groups. The ratio of concentrations of the competitive ring opening products will reflect the ratio of the rates. The Hammett equation will allow quantification of the data, giving a measure of the electronic effects of substituents on the transition state. Syntheses of appropriate radical precursors and authentic products of the competition reactions will be presented. |
| |
|
Physical Organic, Combinatorial, Materials, Molecular Recognition
8:00 PM-10:00 PM, Tuesday, March 30, 2004 Anaheim Convention Center -- Hall A, Poster
Division of Organic Chemistry
The 227th ACS National Meeting, Anaheim, CA, March 28-April 1, 2004
|