Methylenecyclopropane
Methylenecyclopropane is an organic compound with the formula. It is a hydrocarbon which, as the name suggests, is derived from the addition of a methylene substituent to a cyclopropane ring. It is a colourless, easily condensed gas that is used as a reagent in organic synthesis.
Synthesis
Methylenecyclopropane can be synthesized via an intramolecular cyclisation reaction from methallyl chloride by treatment with a strong base such sodium amide—sodium tert-butoxide or sodium bis(trimethylsilyl)amide with further treatment by sodium tert-butoxide. Sodium tert-butoxide is used to isomerize byproduct 1-methylcyclopropene into methylenecyclopropane.Reactions
Being a strained and unsaturated molecule methylenecyclopropane undergoes many reactions, especially in the presence of metal catalysts.For example, methylenecyclopropanes can be converted to cyclobutenes in the presence of a platinum catalyst. This can be considered similar to the ring expansion seen in vinylcyclopropane rearrangements
Substituted methylenecyclopropanes can also be involved in trimethylenemethane cycloaddition reactions.