Grignard reaction product involving a ketone

[chris_0101]

Homework Statement

Basically I have to show the product of this reaction:

Homework Equations

Grignard reaction mechanism:
The conversion of a ketone to an alcohol

The Attempt at a Solution

My attempt of this reaction produces an alcohol with two ethyl groups attached to the central carbon as well as a phenyl group and an OH group attached to the central carbon, so the IUPAC name would be 3-phenyl-3-pentanol.

However, the answer is:

Can someone please explain why the reaction produced an alkene instead of an alcohol. I do not know why this occurred and need some clarification. Also, when does this extra step occur.

Thanks.

 

[pmsrw3]

Think a little about step 3.

 

[chris_0101]

What occurs is step 3? I know that the H2SO4 is deprotonated to become HSO4. This produces the alcohol part of the compound, which is what I got. I am going to assume that deprotonation of HSO4 occurs, thus producing water and the alkene as shown in the answer. Is this right?

 

[pmsrw3]

Look up "dehydration". Sulfuric acid is a powerful dessicant.