The correct answer is (2) less +I effect found in butanone.
Let's delve into the explanation for why butanone is less reactive than propanol toward nucleophilic addition reactions.
Nucleophilic Addition Reaction:
In nucleophilic addition reactions, a nucleophile attacks an electrophile, resulting in the addition of the nucleophile to the substrate. In the context of carbonyl compounds (like butanone and propanol), the carbonyl carbon is the electrophile.
Influence of Substituents:
The reactivity of a carbonyl compound can be influenced by the nature of substituents attached to the carbonyl group. One important factor is the inductive effect (+I effect), which is the ability of a substituent to donate electrons through sigma bonds.
Analysis of Options:
1. More +I effect found in butanone: If butanone has more electron-donating groups (more +I effect), it would make the carbonyl carbon less electron-deficient (less electrophilic) and potentially more reactive. This contradicts the idea that butanone is less reactive.
2. Less +I effect found in butanone: If butanone has less electron-donating groups (less +I effect), it would result in a more electron-deficient (more electrophilic) carbonyl carbon. This aligns with the statement that butanone is less reactive.
3. More +I effect found in propanol: The +I effect in propanol is not directly relevant to the reactivity of butanone. The question is comparing butanone and propanol, not propanol and its +I effect.
4. Less +ve charge found on the carbonyl group of propanol: The charge on the carbonyl carbon is not directly related to reactivity. It's more about the electron density around the carbon.
Conclusion:
The correct explanation is that butanone is less reactive than propanol because it has less electron-donating (+I) effect. This makes the carbonyl carbon in butanone more electrophilic, facilitating nucleophilic addition reactions to a lesser extent compared to propanol. |
