Good Leaving Groups Practice Problems

Using the K_eq values, identify the reaction that has the best leaving group.

For which of these reactions would the rate of formation of the carbocation be higher?

For which of these reactions would the rate of formation of the carbocation be higher?

Which of the following compounds makes a better leaving group when both are reacted in DMSO?

Which of the following compounds has a better leaving group? Justify your answer.

Arrange the following in order of their decreasing leaving group abilities.

For the two pairs of anions given below, state which one in each pair is a better leaving group.

a. ⁻NH₂ and F⁻

b. Br⁻ and Cl⁻

The reaction of (R)-1-fluoro-1-iodopropane with sodium ethoxide is given below.

(R)-1-fluoro-1-iodopropane + sodium ethoxide → (R)-1-ethoxy-1-fluoropropane + NaI

a. Draw perspective structures of the reactants, transition state, and the products.
b. Is there a retention or inversion of configuration in the product? Is this consistent with the S_N2 reactions?
c. Why is iodide substituted and not fluorine?