 And here we need to find the different ways by which this alcohol can be synthesized using Grignard reaction. Now here as you can see we have a tertiary alcohol and it is the ketones that react with Grignard reagents that give tertiary alcohols. Now in this tertiary alcohol we have three different alkyl groups. So that means the alkyl group from the Grignard region can come from any of these groups. And this CO bond here would be the source of our carbonyl compound. So based on this let's explore the possibilities. So if our ketone has CH3 and CH2 CH3 as the alkyl groups in that case our reactants would be CH3 C double bond O CH2 CH3. So these are the two alkyl groups of the ketone and the structure of the Grignard region would be this. So here it is this carbon of the Grignard region that has a partial negative charge and carries out a nucleophilic addition reaction on our ketone. Now what if our ketone is formed between this group and our methyl group? In that case our reactants would be C double bond O CH3 plus CH3 CH2 Ng Br. So in this case as you can see the ethyl group comes from the Grignard reagent. Now there is one more possibility when the carbonyl carbon belongs to the ethyl group and this particular group. In that case our reactants would look like this C double bond O CH2 CH3 plus in this case the only group that needs to be added here is the methyl group and the methyl group would come from our Grignard reagent. So the Grignard region would be methyl, magnesium, bromide. So these are the various ways in which we can prepare this particular tertiary alcohol.