# What will be the product of this reaction?

We have an alpha beta unsaturated ether, along with a keto group in the same compound, which is being treated with a grignard reagent shown (assume the grignard reagent is in excess). Will it only attack the carbonyl group, or are things different here?

This reaction is one of a special kind. The one and onlyend product is 3-hydroxy,3- methylcyclohexan-1-one. As the Grignard reagent is in excess, and it is an $\alpha$- $\beta$ unsaturated ketone, there is a possibility of undergoing two different type of reaction mechanisms. But Surprisingly, both will give the same ultimate end product after two steps.
Now, the minor mechanism is the process of conjugated addition of the methyl group to that $\alpha$-$\beta$ unsaturated ketone. But again after tautomerisation and hydrolysis it actually forms the same compound, which is 3-hydroxy,3-methyl cyclohexan-1-one. The reaction scheme is shown below,
So, it is seen that however the presence of excess reagent may interfere with the reaction mechanism but the end product is $100$$\%$ $3$-hydroxy,$3$-methylcyclohexan-$1$-one.
• @Waylander, I am assuming that the hydrolysis is done in such acidic conditions which can also protonate the oxygen of the ether and the there will be a $S_N1$ type attack of water molecule at the tertiary carbocation formed after $\ce{MeOH}$ leaves the system. Actually as there is a possibility of tertiary carbocation formation, I think slightly acidic conditions can also facilitate the leaving of $\ce{MeOH}$ and perform the hydrolysis. – Soumik Das May 12 '18 at 5:32