Chapter 13, Problem 71CP

(a)

Interpretation Introduction

Interpretation:

The mechanism for the given conversion has to be identified and the stereochemical outcome has to be justified.

Concept introduction:

Ring-opening of epoxide: The epoxide ring is highly strain and readily undergoes reaction with strong nucleophile result in the ring-opening reaction.

Acid-catalyzed ring-opening of epoxide: The epoxide ring is protonated and the nucleophile attack depends on the electronic or steric effect (nature of epoxide).

Regiochemistry: when the epoxide is unsymmetrical, the nucleophile attack at the more substituted position of the protonated epoxide ring.

Base catalyzed ring opening of epoxide:

The nucleophile will attack at the less substituted position under basic conditions

(b)

Interpretation Introduction

Interpretation:

The product of the given process has to be predicted.

Concept introduction:

Sharpless epoxidation: An Alkene containing a Hydroxyl group in the allylic position is called as Allylic alcohols. Allylic position is the position next to $\text{C=C}$ bond.

Sharpless catalyst consists of Titanium tetraiospropoxide and one enantiomer of Diethyl tartrate ($\text{DET}$)

A chiral complex is formed with Titanium tetraisopropoxide and with either $\text{+DET}$ or $\text{-DET}$, and this complex serves as the chiral catalyst.