The chemical investigation of the structure of crosslinks in polymers is rather difficult, but analogous low molecular weight substances can serve as models. Dehydrodimers of 1,5,9-cyclododecatriene (isomers with a different position of the double bonds) were prepared by reaction with di-t-butyl peroxide as model compounds of crosslinked 1,4-polybutadiene. A metathesis reaction of the mixture of the dehydrodimers was carried out with both 4-octene and 3-hexene using the catalyst WCl 6/(CH 3) 4Sn. The various products were identified by combination of gas chromatography (GC) and mass spectrometry (MS); cyclopentenyl and cyclohexenyl compounds, some of them known from the metathesis degradation of crosslinked 1,4-polybutadiene, were characteristic subgroups. The products gave evidence of the partial double bond shift during dehydrodimerization. In addition, kinetic investigations of the metathesis reaction were carried out. Some of the products were formed from the beginning, and others only after an induction period. At the end of the reaction, the linear units of the dehydrodimers were recovered completely in products detectable by GC, in contrast to dehydrodimerized units. The consequences for an investigation of the polymer crosslinks by metathesis degradation are discussed.