Chapter 21, Problem 21.49P

Interpretation Introduction

Interpretation:

A reaction roadmap have to be made for the reactions in the study Guide problem 20.55 and chapter 21.

Concept Introduction:

Addition Reaction: It is defined as chemical reaction in which two given molecules combines and forms product. The types of addition reactions are electrophilic addition, nucleophilic addition, free radical additions and cycloadditions. Generally, compounds with carbon-hetero atom bonds favors addition reaction.

Addition of alcohols to aldehydes and ketones: Aldehyde reacts with alcohol to form Hemiacetals or acetals.

Example: the reaction of methanol with ethanol to form hemiacetals or acetals.

Unsaturated compound: The nucleophile reacts with $\alpha ,\beta$- unsaturated aldehyde or ketones forming either direct addition product or conjugate addition product. When the nucleophile is a weak base conjugate addition product predominates.

The alkylation at the β carbon of ketone or aldehyde is done by the following mechanism;

(1) Alkylating the β carbon via enamine intermediate.

(2) Alkylating the β carbon via a Michael reaction.

Addition Reaction:

• It is a type of reaction in which two reactants adding together to form a single product.
• It can be said as a reverse reaction of elimination reaction.
• It is a characteristic reaction of alkane.

Hydrogenation reaction is an addition reaction in which addition of hydrogen to an unsaturated molecule occurs