Rearrangement VII. Pyrolysis of Isopentyl and Neopentyl p-Toluenesulfonates

The pyrolysis of isopentyl and neopentyl P-toluenesulfonates in the liquid phase at 200°gave 2-methyl-1-propene (3.0 and 4.3%), 2-methyl-1-butene (10.8 nad 14.5%), 3-methyl-1-butene (12.1 and 2.3%), 2-methyl-2-butene (59.7 and 59.6%), 2-methylpropane (3.4 and 5.1%), and 2 methylbutane (11.0 and 14.2%). The former gave predominantly rearranged hydrocarbons, but the latter gave exclusively rearranged hydrocarbons. The ratio of the saturated to unsaturated hydrocarbons was 1:6 and 1:4.2, respectively. It was suggested that the pyrolysis may proceed, at least in part, through a free radical process on the basis of (1) a change in the product composition and a decrease in yield caused by the addition of a free radical inhibitor,(2) the close resemblance of the product composition to that from a simple free radical reaction of isopentyl system, and (3) an ESR study