Diels-Alder reactions of hexachlorocyclopentadiene led to the formation of the adducts I from nitroethylene, VI after hydrolysis of the adduct from itaconic anhydride, and X from dimethyl acetylenedicarboxylate. The nitro adduct I was converted to a sodium salt I1 which yielded the chloro (IVa) and bromo (IVb) derivatives on halogenation. The failure of I1 to undergo the Nef or related solvolysis reactions is attributed in part to an inductive effect of the chlorine ...
![Bicyclo[2.2.1]hept-5-ene-2-carboxylicacid, 1,4,5,6,7,7-hexachloro- Structure](https://image.chemsrc.com/caspic/271/2157-20-2.png)