Organic Chemistry Read
The best method for preparing nonhalogenated cyclopropanes is the Simmon-Smith reaction. This reaction, first investigated at the Du Pont company, does not involve a free carbene. Rather, it utilizes a carbenoid—a reagent with carbene-like reactivity. When diiodomethane is treated with a specially prepared zinc-copper alloy, (iodomethyl) zinc iodide, is formed.