organo metallic compound................alkyl group linked with MgX

in which alkyl- or aryl-magnesium halides (Grignard reagents), which act as nucleophiles, attack electrophilic carbon atoms that are present within polar bonds (e.g., a carbonyl group, see below) to yield a carbon-carbon bond (compare to Wittig reaction), thus altering hybridization about the reaction cente
Grignard reagents are formed via the action of an alkyl or aryl halide on magnesium metal.[6] The reaction is conducted by adding the organic halide to a suspension of magnesium in an ether, which provides ligands required to stabilize the organomagnesium compound. Typical solvents are diethyl ether and tetrahydrofuran. Oxygen and protic solvents such as water or alcohols are not compatible with Grignard reagents. The reaction proceeds through single electron transfer.

R-Mg-X is an organo metallic compoud .