Questions: Which of the following compounds will undergo an SN2 reaction most readily? (CH3)2CHI (CH3)2CHCH2CH2CH2Cl (CH3)3CCl (CH3)3CCH2I (CH3)2CHCH2CH2CH2I

Solution Steps

The SN2 reaction is a bimolecular nucleophilic substitution reaction where the nucleophile attacks the electrophilic carbon from the opposite side of the leaving group, resulting in a single transition state. The reaction rate is highly dependent on steric hindrance around the electrophilic carbon. Less hindered (less substituted) carbons are more reactive in SN2 reactions.

Let's analyze the steric hindrance of each compound:

1. \((\mathrm{CH}_3)_2\mathrm{CHI}\): This is a secondary alkyl iodide. Iodine is a good leaving group, but the secondary carbon is somewhat hindered.
2. \((\mathrm{CH}_3)_2\mathrm{CHCH}_2\mathrm{CH}_2\mathrm{CH}_2\mathrm{Cl}\): This is a primary alkyl chloride. Chlorine is a less effective leaving group compared to iodine, but the primary carbon is less hindered.
3. \((\mathrm{CH}_3)_3\mathrm{CCl}\): This is a tertiary alkyl chloride, which is very hindered and not favorable for SN2 reactions.
4. \((\mathrm{CH}_3)_3\mathrm{CCH}_2\mathrm{I}\): This is a primary alkyl iodide, which is less hindered and has a good leaving group.
5. \((\mathrm{CH}_3)_2\mathrm{CHCH}_2\mathrm{CH}_2\mathrm{CH}_2\mathrm{I}\): This is a primary alkyl iodide, which is less hindered and has a good leaving group.

For SN2 reactions, primary alkyl halides are generally more reactive than secondary or tertiary ones due to less steric hindrance. Among the primary alkyl halides, iodides are more reactive than chlorides due to the better leaving group ability of iodine.

• \((\mathrm{CH}_3)_3\mathrm{CCH}_2\mathrm{I}\) and \((\mathrm{CH}_3)_2\mathrm{CHCH}_2\mathrm{CH}_2\mathrm{CH}_2\mathrm{I}\) are both primary iodides, but \((\mathrm{CH}_3)_3\mathrm{CCH}_2\mathrm{I}\) has a slightly more hindered environment due to the presence of the bulky \((\mathrm{CH}_3)_3\mathrm{C}\) group.

Final Answer