Chapter 4, Problem 4.54P

Interpretation Introduction

Interpretation:

All the constitutional isomers that have the molecular formula ${\text{C}}_{\text{4}}{\text{H}}_{\text{6}}$ are to be drawn.

Concept introduction:

Constitutional isomers have the same molecular formula. They have a difference in the connectivity of the atoms. They do not interconvert and can be separated from each other. When drawing the constitutional isomers for a given molecular formula, the first step is to determine the IHD. This helps to find out the possible number of double bonds, triple bonds, or rings in each isomer. The contribution of each double bond in a molecule to the molecule’s index of hydrogen deficiency is 1. The contribution of each triple bond in a molecule to the molecule’s index of hydrogen deficiency is 2. The contribution of each ring in a molecule to the molecule’s index of hydrogen deficiency is 1. Then all possible isomers are drawn, omitting double bonds, triple bonds, and halogen atoms. Finally, double and triple bonds are added at various locations to generate as many structures as possible. Halogen atoms are added to form as many unique connectivities as possible.