Predict and draw the structure of the product of the reaction of the following
substrates with the given reducing agent.
2-hexanone mixed with hexanoic acid with
(i) NaBH4
(ii) LiAlH4
2-hexanol
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To predict the structure of the products of the reactions between 2-hexanone and hexanoic acid with NaBH4 and LiAlH4, we need to consider the reduction reactions that occur with these reducing agents.
(i) Reaction with NaBH4:
NaBH4 is a mild reducing agent that can selectively reduce the carbonyl group (C=O) of ketones and aldehydes to form alcohol groups (OH). In this case, 2-hexanone will be reduced to 2-hexanol by NaBH4.
The structure of 2-hexanol is: CH3CH2CH2CH2CH(OH)CH3
Hexanoic acid, on the other hand, is a carboxylic acid and will not undergo reduction with NaBH4. Therefore, it will remain unchanged.
(ii) Reaction with LiAlH4:
LiAlH4 is a strong reducing agent that can reduce a wide range of functional groups, including carbonyl groups (C=O), to alcohol groups (OH). In this case, both 2-hexanone and hexanoic acid will be reduced by LiAlH4.
The structure of the product of 2-hexanone with LiAlH4 will be 2-hexanol, the same as with NaBH4.
The structure of the product of hexanoic acid with LiAlH4 will be hexanol, as the carboxylic acid functional group (-COOH) is reduced to an alcohol group (-OH).
The structure of hexanol is: CH3CH2CH2CH2CH2CH2OH
So, to summarize:
(i) Reaction with NaBH4:
2-hexanone + NaBH4 → 2-hexanol
Hexanoic acid + NaBH4 → No reaction
(ii) Reaction with LiAlH4:
2-hexanone + LiAlH4 → 2-hexanol
Hexanoic acid + LiAlH4 → Hexanol
To predict and draw the product of a reaction, it is important to understand the reactivity of the substrates and the reducing agents involved. In this case, we have 2-hexanone and hexanoic acid as substrates, and two reducing agents: NaBH4 and LiAlH4. Let's go through each reaction and understand the process of reduction.
(i) Reaction with NaBH4:
NaBH4 is a mild reducing agent that typically reduces carbonyl compounds (like ketones and aldehydes) to their respective alcohols. In this case, 2-hexanone and hexanoic acid both contain a carbonyl group. The reaction with NaBH4 will reduce the ketone group in 2-hexanone and the carboxylic acid group in hexanoic acid to their respective alcohol groups.
To draw the structure of the product:
1. Identify the carbonyl group in 2-hexanone and the carboxylic acid group in hexanoic acid.
2. Replace the carbonyl oxygen in 2-hexanone with a hydroxyl group (-OH) to form 2-hexanol.
3. Replace the carboxylic acid group in hexanoic acid with a hydroxyl group (-OH) to form hexanol.
The product of the reaction between 2-hexanone and hexanoic acid with NaBH4 is 2-hexanol and hexanol.
(ii) Reaction with LiAlH4:
LiAlH4 is a stronger reducing agent compared to NaBH4 and can also reduce carbonyl groups. However, LiAlH4 is more reactive and has the ability to reduce carboxylic acid groups directly to primary alcohols.
To draw the structure of the product:
1. Identify the carbonyl group in 2-hexanone. Replace the carbonyl oxygen with a hydroxyl group (-OH) to form 2-hexanol.
2. Identify the carboxylic acid group in hexanoic acid. Replace the carboxylic acid group with a primary alcohol group (-OH) to form hexanol.
The product of the reaction between 2-hexanone and hexanoic acid with LiAlH4 is 2-hexanol and hexanol.
It is important to note that the reaction conditions, such as solvent, temperature, and stoichiometry, can have an impact on the outcome of the reaction. These factors were not specified in the question, so the above predictions are based on the general reactivity of the substrates and reducing agents.