Determine whether the given nucleophile favors an S_N1 or S_N2 reaction.

With the given solvent, what kind of substitution reaction is most likely to take place?

Draw a plausible mechanism for the substitution reaction shown below.

Consider the substitution reaction below:

What is (are) its product(s)? Does a rearrangement occur?

The given benzylic iodide is inert toward S_N1 and S_N2 reactions. Explain why.

The reaction of 2-chlorobutane with sodium methoxide in methanol forms 2-methoxybutane. When small amounts of potassium iodide are added to the reaction mixture, the rate of the formation of 2-methoxybutane increases. Explain why.

In the presence of a strong electrophile, the following reaction should have occurred via bimolecular substitution, yet rearrangement proceeded. Suggest a mechanism to explain the enhanced rate and ­rearrangement observed in this unusual reaction. Ignore stereochemistry. Note that “Me” is the abbreviation for methyl.