is the active reagent in the Simmons-Smith reaction
. For example, iodomethylzinc iodide, formed in situ
and a zinc-copper couple
reacts with cyclohexene
to give norcarane
Iodomethylzinc iodide may also be generated by the reaction of diazomethane with zinc iodide, or by the reaction of methylene iodide with diethylzinc.