Synthon

In chemistry, a synthon is an imaginary or hypothetical chemical species used in retrosynthetic analysis, a method of breaking apart complicated organic compounds to plan out how to make them with organic synthesis.^[1] The term was coined by chemist E. J. Corey, who won the Nobel Prize in Chemistry for his work on synthesis.

Most synthons are too unstable to exist in a real reaction. A real synthesis instead uses a synthetic equivalent for a synthon. For example, Grignard reagents like methylmagnesium chloride (CH₃MgCl) are synthetic equivalents of carbanions like methylide (CH−3).