Cyclopropanation is a chemical reaction that involves the formation of a cyclopropane ring, which is a three-membered carbon ring. This process typically occurs when a carbene or a carbenoid reacts with an alkene, resulting in the addition of two carbon atoms to the double bond of the alkene. The reaction is significant in organic chemistry because cyclopropane rings are highly strained and can lead to unique chemical properties. Cyclopropanation is often used in the synthesis of various organic compounds, including pharmaceuticals and agrochemicals, due to its ability to create complex molecular structures efficiently.