 Iodomethylzinc iodide

Iodomethylzinc iodide is the active reagent in the Simmons–Smith reaction.For example, iodomethylzinc iodide, formed "in situ" from diiodomethane and a zinc-copper couple reacts with cyclohexene to give norcarane (bicyclo[4.1.0]heptane).