1,1-Bis(chloromethyl)ethylene is the organic compound with the formula CH<sub>2</sub>=C(CH<sub>2</sub>Cl)<sub>2</sub>. It is a colorless liquid. Featuring two allylic chloride substituents, it is dialkylating agent.
It is prepared from pentaerythritol via a multistep procedure, beginning with the partial chlorination. The compound reacts with diiron nonacarbonyl to give the complex of trimethylenemethane Fe(÷<sup>4</sup>-C(CH<sub>2</sub>)<sub>3</sub>)(CO)<sub>3</sub>. It is also a precursor to [1.1.1]-propellane.