Abstractα,ω‐Dimethoxycarbonyl substituted polyenes were synthesized by co‐metathesis between 1,5‐cyclooctadiene (1) and dimethyl 3‐hexenedioate (2) by use of the catalytic system WCl6/Sn(CH3)4. The ability of2for co‐metathesis with1was proved by determination of the distribution of low molecular weight products in terms of reaction time and2/1mole ratio. For these studies, high values of2/1ratios (0,5–4) were chosen in order to obtain lowest molecular weight co‐metathesis products (3b–3e). Metathesis involved preferentially the double bonds in the neighbourhood of the ester groups. At lower values of the2/1ratio (0,012–0,061) α,ω‐difunctional prepolymer