Examkin

Question

Difficulty: MediumAlkanals and Alkanones: Oxidation, Reduction, and Distinction Tests

What is the IUPAC name of the organic compound formed by the reduction of butan-2-one using lithium tetrahydridoaluminate(III) (LiAlH4LiAlH_4)?

Answer: butan-2-ol / 2-butanol / butan 2 ol / 2-Butanol / Butan-2-ol

Answer

butan-2-ol
The reduction of alkanones (ketones) with reducing agents such as LiAlH4LiAlH_4 converts the carbonyl group (C=OC=O) into a secondary alcohol group (−CH(OH)−-CH(OH)-). Since the carbonyl carbon in butan-2-one is at position 2, the resulting hydroxyl group is also at position 2, yielding the secondary alcohol butan-2-ol.

Step-by-Step Solution

1
Identify the functional group and carbon chain length of the reactant.
Butan-2-one is a 4-carbon alkanone (ketone) with the carbonyl group at carbon-2 (CH3−CO−CH2−CH3CH_3-CO-CH_2-CH_3).
Determining the reactant structure establishes the expected reduction product.
2
Apply the reduction reaction mechanism for alkanones.
Reducing agents such as LiAlH4LiAlH_4 or NaBH4NaBH_4 reduce alkanones to secondary alcohols by adding hydrogen across the C=OC=O double bond.
The carbonyl group (C=OC=O) is converted to a secondary alcohol group (−CH(OH)−-CH(OH)-).
3
Name the resulting alcohol using IUPAC nomenclature.
CH3−CH(OH)−CH2−CH3CH_3-CH(OH)-CH_2-CH_3 is named butan-2-ol.
The hydroxyl group (−OH-OH) remains on carbon-2 of the 4-carbon parent chain.

Key Concept

Reduction of alkanones to secondary alcohols
Estimated Time:1m 0s
Rate this question

Topics

Alkanals and Alkanones: Oxidation, Reduction, and Distinction Tests

More questions from this topic