During the reaction between potassium hydroxide and 2-bromopropane, 2-propanol is formed. Suggest the correct mechanism for this reaction.
Choose an answer:
A) $S_N2$
B) $S_N1$
C) Neither $S_N1$ nor $S_N2$
Answer (2)
The reaction between potassium hydroxide and 2-bromopropane occurs via the S N 2 mechanism, where the hydroxide ion attacks the carbon attached to bromine while bromine leaves simultaneously, forming 2-propanol. An S N 1 mechanism is less likely due to the strength of the nucleophile and the structure of the substrate. Therefore, the correct answer is A) S N 2 .
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The reaction between potassium hydroxide (KOH) and 2-bromopropane (C₃H₇Br) leads to the formation of 2-propanol (C₃H₇OH). To understand which mechanism is involved in this conversion, we need to consider the structures and conditions that favor different substitution reactions.
Background Information :
S N 2 Mechanism : This is a bimolecular nucleophilic substitution reaction. It involves a single step where the nucleophile attacks the electrophilic carbon, displacing the leaving group simultaneously. This mechanism is favored in primary and some secondary alkyl halides, especially in polar aprotic solvents.
S N 1 Mechanism : This is a unimolecular nucleophilic substitution reaction. It involves two steps: the leaving group departs first, forming a carbocation, followed by nucleophilic attack. This is favored in tertiary and some secondary alkyl halides, especially in polar protic solvents.
Analyzing the Reactants :
2-Bromopropane is a secondary alkyl halide. Secondary halides can undergo both S N 1 and S N 2 reactions depending on conditions.
Potassium Hydroxide is a strong nucleophile, generally favoring S N 2 reactions when steric hindrance is low.
Reasoning :
In this case, the use of a strong nucleophile like KOH in a substrate that is not too sterically hindered (secondary) would typically proceed through an S N 2 mechanism, especially if solvents and conditions do not strongly favor carbocation formation (as in S N 1 ).
Conclusion :
The correct mechanism for the reaction between potassium hydroxide and 2-bromopropane leading to the formation of 2-propanol is likely a) S N 2 .
In summary, the reaction between potassium hydroxide and 2-bromopropane most likely follows an S N 2 mechanism, given the nature of the reactants and typical reaction conditions.
