The diol shown is treated with dilute acid. Water is lost from the carbon whose cation is better stabilised, and then a ring bond migrates. Which structure is the major product?

AStructure A
BStructure B
CStructure C
DStructure D

Answer: C

The diol is 1-(hydroxydiphenylmethyl)cyclobutan-1-ol. The diphenylcarbinyl cation forms, and a ring

CH X_{2}

migrates from the cyclobutane carbon to it, which relieves ring strain by enlarging the four-membered ring to five. The carbonyl is left on the former cyclobutanol carbon, giving 2,2-diphenylcyclopentan-1-one.

Practice Alcohols, Phenols and Ethers More on Pinacol rearrangement products of drawn diols

Previous questionNext question

More questions on Pinacol rearrangement products of drawn diols

The diol shown is treated with dilute acid. Take the convention that hydride migrates in preference to methyl, and that water is lost from t... JEE Main level
The diol shown is treated with dilute acid; ignore its stereochemistry. Water may be lost from either carbinol carbon, and either alkyl grou... JEE Main level
For the pinacol rearrangement of the diol shown (dilute H2SO4, warm), choose all correct statements. JEE Main level
The cyclic diol shown is heated with dilute acid to give a single carbonyl product by loss of one molecule of water. Choose all correct stat... JEE Advanced level
The diol shown is treated with cold dilute acid. Choose all correct statements. JEE Advanced level
The diol shown is first heated with dilute H2SO4. The organic product is then treated with excess iodine in sodium hydroxide solution and th... JEE Advanced level