Which of the following alcohols will not undergo oxidation: a butanol b butan 2 ol c 2 methylbutan 2 ol d 3 methylbutan 2 ol?

The alcohol that will not undergo oxidation among the given options is 2-methylbutan-2-ol.

Understanding Alcohol Oxidation

The ability of an alcohol to undergo oxidation depends on the type of alcohol, specifically the number of carbon atoms attached to the carbon bearing the hydroxyl (-OH) group. Alcohols are generally classified into primary, secondary, and tertiary based on this structure:

Primary Alcohols (1°): The carbon atom bonded to the hydroxyl group is attached to only one other carbon atom. These alcohols readily undergo oxidation to form aldehydes, which can then be further oxidized to carboxylic acids.
Secondary Alcohols (2°): The carbon atom bonded to the hydroxyl group is attached to two other carbon atoms. These alcohols oxidize to form ketones.
Tertiary Alcohols (3°): The carbon atom bonded to the hydroxyl group is attached to three other carbon atoms. Tertiary alcohols generally do not undergo oxidation under typical oxidizing conditions because they lack a hydrogen atom on the carbon bearing the hydroxyl group, which is essential for the oxidation reaction. Stronger, harsher conditions might lead to carbon-carbon bond cleavage, but this is not considered a typical alcohol oxidation.

Analysis of the Given Alcohols

Let's classify each alcohol provided in the options to determine its oxidation behavior:

Butanol (a): This term typically refers to n-butanol (butan-1-ol), which is a primary alcohol.
- Structure: CH₃-CH₂-CH₂-CH₂-OH
- Oxidation: Will oxidize to butanal (an aldehyde) and then to butanoic acid (a carboxylic acid).
Butan-2-ol (b): This is a secondary alcohol.
- Structure: CH₃-CH₂-CH(OH)-CH₃
- Oxidation: Will oxidize to butanone (a ketone).
2-Methylbutan-2-ol (c): This is a tertiary alcohol.
- Structure:
```
     CH₃
     |
CH₃-C-CH₂-CH₃
     |
     OH
```
- The carbon atom bonded to the -OH group is attached to three other carbon atoms (one methyl group and one ethyl group).
- Oxidation: Will not undergo oxidation under normal conditions.
3-Methylbutan-2-ol (d): This is a secondary alcohol.
- Structure:
```
     CH₃
     |
CH₃-CH-CH(OH)-CH₃
```
- The carbon atom bonded to the -OH group is attached to two other carbon atoms (one methyl group and one isopropyl group).
- Oxidation: Will oxidize to 3-methylbutan-2-one (a ketone).

Summary of Alcohol Oxidation Behavior

Alcohol Type	Structure around -OH carbon	Oxidation Behavior	Example from Options (if applicable)
Primary (1°)	Attached to 1 C atom	Oxidizes to aldehyde, then to carboxylic acid	Butanol (Butan-1-ol)
Secondary (2°)	Attached to 2 C atoms	Oxidizes to ketone	Butan-2-ol, 3-Methylbutan-2-ol
Tertiary (3°)	Attached to 3 C atoms	Generally does not oxidize	2-Methylbutan-2-ol

Based on the classifications, 2-methylbutan-2-ol is the only tertiary alcohol among the choices, and therefore, it will not undergo oxidation.