NEETChemistryHydrocarbons
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Transformation of but-1-ene to butanal can be achieved using B ₂ H ₆ followed by H ₂ O ₂/ OH ^- and subsequently reacting the product with Pyridinium Chlorochromate (PCC). Reason (R): Hydroboration-oxidation of but-1-ene yields butan-1-ol via anti-Markovnikov addition of water, and primary alcohols
Options
- ABoth Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
- BBoth Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of Assertion (A).
- CAssertion (A) is true but Reason (R) is false.
- DAssertion (A) is false but Reason (R) is true.
Correct answer
A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
Step-by-step solution
The Assertion is true: the sequence of hydroboration-oxidation ( B ₂ H ₆ followed by H ₂ O ₂/ OH ^- ) converts a terminal alkene (but-1-ene) to a primary alcohol (butan-1-ol). Subsequent oxidation with a mild oxidizing agent like PCC converts the primary alcohol to an aldehyde (butanal) without over-oxidizing it to a carboxylic acid. The Reason is also true and correctly explains the Assertion: the regioselectivity of hydroboration-oxidation follows anti-Markovnikov addition, placing the hydroxyl group on the less