Question

Benzyl bromide, on treatment with a nucleophile - triphenylphosphine, is then made to react with n-Butyl lithium - a strong base to give a phosphorus ylid.
Which of the following, on treatment with the said ylid - would yield the hydrocarbon:

• A. benzaldehyde
• B. phenylacetaldehyde
• C. hexan-1-one
• D. cyclohexanone

Answer 1

The correct option is D

cyclohexanone

The first part - the question statement generates an ylid (phosphorus).
This can olefinate (make an alkene) the carbonyl carbon, replacing the double bond with O
with a double bond with carbon.