Reaction of Grignard Reagents with Aldehydes and Ketones

Grignard reagents, which are obtained by reaction of alkyl, aryl, acetylenic halides, are very important instruments of synthesis. A Grignard reagent provides a nucleophilic carbon which can be used for bonding to another carbon. (The carbon bonded to magnesium in the Grignard reagent is nucleophilic, being the more electronegative end of the bond with magnesium.) For example, Grignard reagent carbon reacts with electropositive carbonyl carbons. Grignard reagents also react to form new carbon-carbon bonds with esters, nitriles, epoxides, and carbon dioxide carbons. (Grignard reagents can't be used in the presence of acidic protons. The acid in the mechanism above is only applied in the reactionís last stage.)