Chapter 9, Problem 9.69P

Interpretation Introduction

(a)

Interpretation: The reaction conditions that are needed to convert $\left(\text{R}\right)\text{-2-ethyl-2-methyloxirane}$ to $\left(\text{R}\right)\text{-2-methylbutane-1, 2-diol}$ are to be predicted.

Concept introduction: The opening of an epoxide/oxirane ring is regioselective either it takes place with a strong nucleophile $\left({\text{:Nu}}^{-}\right)$ or an acid $\left(\text{HZ}\right)$. The mechanism of the reaction with ${\text{:Nu}}^{-}$ is ${\text{S}}_{\text{N}}\text{2}$, and the mechanism of the reaction with $\text{HZ}$ is in between ${\text{S}}_{\text{N}}\text{2}\text{and}{\text{S}}_{\text{N}}1$.

Interpretation Introduction

(b)

Interpretation: The reaction conditions that are needed to convert $\left(\text{R}\right)\text{-2-ethyl-2-methyloxirane}$ to $\left(\text{S}\right)\text{-2-methylbutane-1, 2-diol}$ are to be predicted.

Concept introduction: The opening of an epoxide/oxirane ring is regioselective either it takes place with a strong nucleophile $\left({\text{:Nu}}^{-}\right)$ or an acid $\left(\text{HZ}\right)$. The mechanism of the reaction with ${\text{:Nu}}^{-}$ is ${\text{S}}_{\text{N}}\text{2}$, and the mechanism of the reaction with $\text{HZ}$ is in between ${\text{S}}_{\text{N}}\text{2}\text{and}{\text{S}}_{\text{N}}1$.