Is an organometallic chemical reaction in which alkyl, allyl, vinyl, or aryl-magnesium halides (Grignard reagent) is added to a carbonyl group in an aldehyde or ketone or alternatively to a cyanide group. Resulting in an addition product containing an alcohol group.

Commonly used solvents/reagents:
Magnesium turnings
Dibromoethane
Alkyl halides
THF, MeTHF, CPME, MTHP & Dioxane

Example of a typical reaction: