Chapter 5, Problem 5.75P

Interpretation Introduction

(a)

Interpretation:

It is to be identified which two hydrogen atoms in butanal (${\text{C}}_4{\text{H}}_8\text{O}$) can be replaced by $Cl$ atoms to yield constitution isomers having the molecular formula ${\text{C}}_4{\text{H}}_7\text{ClO}$.

Concept introduction:

Constitutional isomers are the isomers having the same molecular formula but different connectivity. For the given structure, replacing hydrogen atoms by halogen atoms attached to different carbon atoms would generate constitutional isomers.

Interpretation Introduction

(b)

Interpretation:

It is to be identified which two hydrogen atoms in butanal (${\text{C}}_4{\text{H}}_8\text{O}$) can be replaced by $Cl$ atoms to yield enantiomers having the molecular formula ${\text{C}}_4{\text{H}}_7\text{ClO}$.

Concept introduction:

Configurational isomers are the stereoisomers which have the same connectivity of atoms and which can’t be interconverted by rotations around single bonds. Enantiomers are the type of constitutional isomers, which are non-superimposable mirror images of each other. For the given structure, replacing the hydrogen atoms on the wedge and dash bond by halogen atoms attached to the same carbon atoms would generate enantiomers.

Interpretation Introduction

(c)

Interpretation:

It is to be identified which two hydrogen atoms in butanal (${\text{C}}_4{\text{H}}_8\text{O}$) can be replaced by $Cl$ atoms to yield conformers having the molecular formula ${\text{C}}_4{\text{H}}_7\text{ClO}$.

Concept introduction:

Conformers are the stereoisomers which have the same connectivity of atoms but which can be interconverted by rotations around single bonds only. For the given structure, replacing hydrogen atoms on the carbon atom having more than two identical groups or atoms will yield conformational isomers.