Rearrangement in the homogeneous elimination kinetics of 3-chloro-2,2-dimethylpropan-1-ol in the gas phase

Article abstract of DOI:10.1002/(SICI)1099-1395(199608)9:8<583::AID-POC818>3.0.CO;2-Z

3-Chloro-2,2-dimethylpropan-1-ol was pyrolysed in a static system at 410-0-459-1°C and 62-179 Torr. The reaction, in a seasoned vessel and in the presence of the free radical suppressor propene, is homogeneous, unimolecular, and follows a first-order rate law. The rate coefficient follows the Arrhenius equation: log k₁ (s^-1)= (13.14±0.15) - (218.8±2.1) kJ mol^-1 (2.303 RT)^-1. The products are isobutene, formaldehyde and HCl gas. The exclusive intramolecular migration of the CH₂OH group to the positively charged carbon atom, from the C - Cl bond polarisation, appears to proceed by way of an intimate ion-pair type of mechanism. The intermediate 3-methylbut-3-en-1-ol, under the reaction conditions, undergoes a six-centered decomposition characteristic of β-hydroxyalkenes to produce isobutene, formaldehyde and HCl. The pyrolysis of the deuterated substrate, 3-chloro-2,2-dimethylpropan-1-[²H]ol, serves to support the mechanistic consideration assumed above.