Chapter 14.5, Problem 14.30P

Interpretation Introduction

Interpretation:

The expected product for the given reaction has to be predicted.

Concept Introduction:

Ether are compounds that contain an oxygen atom that is sandwiched between two R groups.  The R groups may be alkyl, vinyl or aryl.

Epoxides are very much susceptible to the reactions in which the ring is opened.  This ring opening alleviates the ring strain that is present in the three-membered ring.  When a strong nucleophile reacts with an epoxide, the ${\text{S}}_{\text{N}}\text{2}$ reaction mechanism is followed resulting in ring opening.  The general reaction scheme can be given as,

When the epoxide is treated with ${\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}$, the condition becomes acidic and the ring opening reaction takes place.  The nucleophile (alcohol) is a weak nucleophile.  The first step is the protonation of the oxygen in the epoxide ring and the second step is the nucleophilic attack at the more substituted carbon atom.  The general scheme can be depicted as,

Under the acidic conditions, protonation takes place first and that is followed by ${\text{S}}_{\text{N}}\text{2}$ process.