10.2.1.3 Corey-Chaykovsky Reaction

The first stage of the reaction of a sulfur ylide with an aldehydes or ketone compound consists of nucleophilic addition, the resultant adduct then proceeds intramolecular nucleophilic substitution to give an epoxide (Scheme 3). In case of α, β -unsaturated compounds, based on the nucloephilicity of the ylide either epoxide or cyclopropanation could be formed.

Mechanism

Scheme 3

Recently, chiral version of the reaction has been extensively studied for the synthesis of optically active epoxides as the principle shown in Scheme 4. The products are usually obtained with high enantioselectivity.

Scheme 4

Examples