NEETChemistryAldehydes and Ketones
Give plausible explanation for the following statement: Cyclohexanone forms cyanohydrin in good yield but 2,2,6-trimethylcyclohexanone does not.
Options
- AIn 2,2,6 trimethyl cyclohexanone, three methyl groups are present at α−position with respect to the ketonic (>
- B2,2,6-Trimethylcyclohexanone is more reactive than cyclohexanone and therefore undergoes a different reaction
- CThe reaction conditions for cyanohydrin formation are not suitable for 2,2,6-trimethylcyclohexanone.
- D2,2,6-Trimethylcyclohexanone forms a stable complex with cyanide ions, preventing the formation of cyanohydrin
Correct answer
A. In 2,2,6 trimethyl cyclohexanone, three methyl groups are present at α−position with respect to the ketonic (>
Step-by-step solution
Correct Option is : (A) In 2,2,6 trimethyl cyclohexanone, three methyl groups are present at α−position with respect to the ketonic (>C=O) group. Therefore, these groups cause steric hindrance during the nucleophilic attack of CN − ion so cyanohydrin is not formed. Due to the absence of methyl groups in cyclohexanone, there is no steric hindrance and cyanohydrin is formed.