Question
In the following reactions, P, Q, R and S are the major products. The correct statement(s) about P, Q, R and S is(are)
JEE Advanced
Chemistry
Aldehydes and Ketones
2023
JEE Advanced 2023 (Paper 1)
JEE Advanced Chemistry Question (2023) — Solution
Options
- A. Both P and Q have asymmetric carbon(s)
- B. Both Q and R have asymmetric carbon(s)
- C. Both P and R have asymmetric carbon(s)
- D. P has asymmetric carbon(s), S does not have any asymmetric carbon
Answer
D. P has asymmetric carbon(s), S does not have any asymmetric carbon
Step-by-step solution
The cyanide part undergoes reaction with phenyl magnesium bromide followed by acidic water give a ketone. The ketone undergoes reaction with phenyl magnesium bromide again to get a tertiary alcohol. Benzene undergo Friedel craft acylation and gives acetophenone. Acetophenone gives a tertiary alcohol upon reaction with phenyl magnesium bromide. Propanoyl chloride when treated with dibenzyl cadmium gives a ketone. The ketone give tertiary alcohol on reaction with phenyl magnesium bromide. 2-phenyl ethanal gives 1,2-diphenylethanol. The secondary alcohol formed gives a ketone up on reaction with Jone's reagent. The ketone formed undergo nucleophilic addition reaction with hydrogen cyanide to give cyano hydrin which undergo hydrolysis followed elimination give the final product as shown below.
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