Noun
cycloheptadiene (plural cycloheptadienes)
(organic chemistry) Any of several isomeric unsaturated alicyclic hydrocarbons having seven carbon atoms and two double bonds; any derivative of such compound
Aldrichimica Acta Volume 30 No 4 (pdf) from Sigma-Aldrich
Decomposition of 4 in the presence of cis-piperylene at room temperature results in the stereocontrolled formation of trans-cycloheptadiene 27 in 90% ee (96% ee at -78 °C).