Radical ion probes. I. Cyclopropyl-carbinyl rearrangements of aryl cyclopropyl ketyl anions

Abstract

Supplementary Material Available:Plots of log (kx/kMe) vs electronegativity parameters and A* orbital energies (2 pages). Ordering information is given on any current masthead page. (29) Cram, D. J.; Abd Elhafez, F. A. J. Am. Chem. Soc. 1952, 74, (30) Cornforth, J. W.; Cornforth, R. H.; Mathew, K. K. J. Chem. Soc.(31) As an approximation of the magnitude of the angular effect, chargtdipole and dipoltdipole interactions have a cosine dependence, which requires a deviation of over 25' from 180° to alter the interaction by 10%: Hine, J.

Utilization of 1,1-dimethyl-4,6-di-tert-butylspiro[2,5]octa-3,6-dien-5-one as a ‘hypersensitive’ probe for single electron transfer to carbonyl compounds

“…We have found that the radical anion generated from 1,l-dime thyl-4,6-di-tert-but ylspiro [ 2,5 ]octa-3,6-dien-5-one 1 undergoes facile ring opening to the tertiary distonic radical anion at a rate constant estimated to be b 107 s-l (Scheme 1). 1 In this paper, we illustrate the use of this compound as a 'hypersensitive' probe for single electron transfer to carbonyl compounds from several nucleophiles.…”

Copper(II)-salt-promoted oxidative ring-opening reactions of bicyclic cyclopropanol derivatives via radical pathways

“…1) that act as radical ion probes [20] and found that radical intermediates in their reaction pathways undergo efficient 5- exo hexenyl radical cyclization reactions [21], (Fig. 1) [22–30].…”

Characterization of a ‘hypersensitive’ probe for single electron transfer to carbonyl compounds

“…(5)]. 3 The observed difference in the regiochemistry of ring opening of 2 and 13 is explicable on the basis of the Hammond postulate. We infer a late transition state for the ring opening of 13 because this process is end other mi^.^ Hence the kinetics of ring opening are much more sensitive to the stability of the resulting radical.…”