PHOTOLYTIC RING CLEAVAGE OF 1,2-DIARYLCYCLOPROPANES WITH BROMINE IN A NON-POLAR SOLVENT.
Abstract
This work studied further the well established analogy between cyclopropanes and olefins. A series of 1,2-diarylcyclopropanes were prepared and were characterized by their ultraviolet, infrared and NMR spectra. Some of these compounds have not previously been reported. Reactions of these compounds were studied under dark and photolytic conditions with bromine in carbon tetrachloride. No reaction was observed under dark conditions while addition of equimolar amounts of bromine took place under photochemical conditions. The addition product in all cases was the 1,3-dibromo-1,3-diarylpropane. The kinetics of this reaction were studied at low concentrations (0.003 molar) and the influence of the para-substituent on the rates of reaction determined. The reaction rates plotted against Hammett signa values were linear and gave a rho of -0.49 for the cis isomers and a rho of 0.44 for the trans isomers. A mechanism is proposed for the reaction under these conditions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1966
- Accession Number
- AD0487790
Entities
People
- John Melville Hoffmann
Organizations
- Naval Postgraduate School