Gas-phase eliminations. Part XII. Pyrolysis of menthyl and neomenthyl chloride

Abstract

The kinetics of the pyrolysis of menthyl and neomenthyl chlorides to yield hydrogen chloride and a mixture of p-menth-2-ene and p-menth-3-ene have been studied. The results obtained for the former compound, k₁= 10^11·82 exp [–(42,120 ± 470)/RT] sec.^–1 and p-menth-2-ene : p-menth-3-ene = 1:3 are in excellent agreement with those reported. For neomenthyl chloride, k₁= 10^10·74 exp [–(40,080 ± 290)/RT] sec.^–1 and p-menth-2-ene: p-menth-3-ene = 5·7:1. Both reactions are homogeneous and unimolecular when studied in carbon-coated reaction vessels. The results are discussed in terms of the light they shed on the nature of gas-phase elimination from organic halides.