Grignard Reaction

Learn how alkyl halides like alkyl bromides have polar carbon-halogen bonds due to electronegativity differences, creating partial positive and negative charges that are key to the Grignard reaction mechanism.

Magnesium inserts itself into the carbon-halogen bond in anhydrous diethyl ether solvent, inverting the polarity and creating a nucleophilic carbon with partial negative charge that can attack electrophiles.

The Grignard reagent's nucleophilic carbon attacks the electrophilic carbonyl carbon of aldehydes or ketones, forming a new carbon-carbon bond and generating an oxyanion intermediate.

Perform an aqueous acidic workup to protonate the oxyanion, converting it to an alcohol product. The overall reaction combines two carbon fragments into a larger alcohol molecule.

Keep the reaction strictly anhydrous using diethyl ether solvent, as any water molecules will protonate the nucleophilic carbon and destroy the Grignard reagent, rendering it unusable.

Apply Grignard reagents like methyl Grignard to ketone substrates using the same mechanism as aldehydes, resulting in secondary alcohols after acidic workup.

Use excess Grignard reagent with ester substrates to sequentially attack the carbonyl twice: first displacing the alkoxy group to form a ketone intermediate, then attacking that ketone to form a tertiary alcohol product.