Grignard reagents

General formula for grignard reagents

RMgX - R is alkyl group and X is halogen

What is an alkyl group?

It is an alkane molecule with one hydrogen atom missing; it doesn't exist on its own, but is part of another molecule.

How are grignard reagents made?

Refluxing a halogenoalkane with magnesium in dry ether

How would you make carboxylic acid from a grignard reagent?

- Bubble CO2 gas through a grignard reagent in dry ether. Then add a dilute acid.

What happens during the reaction to make carboxylic acid?

A new C-C bond forms between the carbon atom in CO2 and the C-Mg carbon from the grignard reagent. One of the C=O bonds in CO2 is broken to form a COO- group, which is protonated when the dilute acid is added to form -COOH.

How would you make alcohols from a grignard reagent?

Grignard reagents react with aldehydes and ketones to make alcohols. First the carbonyl compound is added to the grignard reagent in dry ether, and then dilute acid is added to the reaction mixture.

What happens during the reaction to make the alcohol?

A new C-C bond forms between the C-Mg carbon atom from the grignard reagent and the C=O carbon of the carbonyl. This causes the C=O bond to break and, when acid is added, and -OH group is formed.

What type of alcohol will be made when a Grignard reagent reacts with an aldehyde?

Secondary (unless it's methanal which makes it primary alcohol)

What type of alcohol will be made when a Grignard reagent reacts with a ketone?

Tertiary