Ethylidencyclohexan ‐ Vorstufe für Allyl‐ und 1,2‐Dimethyl‐allylradikale in der Gasphase

Abstract

Ethylidenecyclohexane ‐ Precursor of Allyl and 1,2‐Dimethylallyl Radicals in the Gas Phase A systematic study of the thermolysis of ethylidenecyclohexane (1) and 1‐vinylcyclohexene (3) was made under VLPP‐MS‐conditions. The major fate of 1 is isomerization to 5‐methyl‐hepta‐1,5‐diene (2) which may then decompose to allyl (7) and 1,2‐dimethylallyl radical (6). The latter is highly unstable and therefore 6 is degraded to isoprene. Minor processes in thermolysis of 1 include further hydrogen elimination to 3 and double bond isomerization to 1‐ethylcyclohexene (4). Both cyclohexene derivates undergo most notably RDA‐fragmentation.