When warmed in dilute sulfuric acid, 1-phenyl-1,2-propanediol undergoes dehydration and rearrangement to give 2-phenylpropanal. its constitutional isomer, 1-phenyl-1-propanone, is not formed under these conditions. following are the mechanistic steps leading to the formation of this unobserved isomer: add a proton to give protonated alcohol 1; break a bond to give carbocation intermediate 2; 1,2-shift to give carbocation intermediate 3; carbocation intermediate 3 is stabilized by resonance delocalization with carbonyl 4; loss of a proton leads to the formation of 1-phenyl-1-propanone. write out the mechanism on a separate sheet of paper, and then draw the structure of carbocation intermediate 3 in the box below. you do not have to consider stereochemistry. you do not have to explicitly draw h atoms. do not include lone pairs in your answer. they will not be considered in the grading.