Chapter 22.11, Problem 28ATS

(a)

Interpretation Introduction

Interpretation: With the mentioned starting material and with any other reagents, an efficient synthesis for compound A has to be proposed.

Concept Introduction:

Retro synthetic analysis:

It is the analysis of the synthetic starting materials for a given compound through its precursors or fragments which are known as synthons. The synthons can be obtained by logical cleavage of the chemical bonds in the compounds. The resulted synthons will be therefore known as logical synthons.

On retro synthetic analysis of the given compound, the synthetic reaction will be predicted to be azo coupling reaction.

Azo Coupling:

It is an electrophilic aromatic substitution reaction in which aryldiazonium salts act as an electrophile and react with activated aromatic rings to form an azo compound.

Example:

(b)

Interpretation Introduction

Interpretation: The cis isomer for the given trans isomer of $\text{PST-1}$ has to be shown.

Concept Introduction:

Geometrical isomerism: It is the phenomenon in which any two compounds will found to have same molecular formula with different spatial arrangement of atoms. The major types of geometrical isomers are cis- and trans-isomers.

Cis-isomer: In the cis-isomer, two same functional groups will be placed adjacent to each other.

Trans-isomer: In the cis-isomer, two same functional groups will be placed opposite to each other.