Free-radical reactions of halogenated bridged polycyclic compounds. Part VII. The addition of methanethiol, bromotrichloromethane, and chloroform to 1,4-dichloronorborn-2-ene

Abstract

The addition of methanethiol, bromotrichloromethane, and chloroform to 1,4-dichloronorborn-2-ene affords solely the products of 1,2-addition to the double bond. No products of skeletal rearrangement are formed. This indicates that in the addition of free-radical reagents to hexachloronorbornadiene and hexachloromethylenenorbornene the formation of products formally derived from 1,2-vinyl migrations of the intermediate radicals must take place by way of intermediate nortricyclyl type radicals, and not by way of a direct fission of a vinylic carbon–carbon bond. A detailed account of the n.m.r. spectra of the addition products, and of some related chlorine-substituted norbornanes and norbornenes is given. A comparative study of the spectral data has allowed product structures to be assigned.