Chapter 11.9, Problem CQ

Interpretation Introduction

Interpretation:

In order to generate a carbonyl group in the third product at basic condition, the occurrence has to be discussed.

Concept Introduction:

Stereochemistry: The spatial arrangement of atoms or groups present in compound.

Epoxides: are more reactive than simple ethers due to three membered ring strains. Reaction of epoxides with nucleophiles opens the ring by which the ring strain is relieved.

Ring opening: Ring opening of epoxide takes place by acid-catalyzed hydrolysis of an epoxide.

Acid-catalyzed hydrolysis of an epoxide:

Ease of dehydration of alcohols:

The ease of acid-catalyzed dehydration of alcohols is in the order as follows,

$\stackrel{{\text{1}}^{\text{o}}\text{alcohol}\text{<}{\text{2}}^{\text{o}}{\text{alcohol < 3}}^{\text{o}}\text{alcohol}}{\to }$

Acid-catalyzed dehydration of primary and secondary alcohols:  Dehydration of primary and secondary alcohols is often accompanied by rearrangement process (shift of hydride or alkyl from $\text{β-}$ carbon to $\text{α-}$ carbon). Primary alcohol with little or no $\text{β-}$ branching undergoes acid-catalyzed dehydration to give a terminal alkene and rearranged alkene. Always the more substituted alkene product predominates.

Addition of halogen across double bond: The reaction of alkene with halogen molecules undergoes electrophilic addition reaction forming 1,2-dihaloalkane compound.