Chapter B, Problem B.29P

Interpretation Introduction

Interpretation:

The structures for $\text{penta-1, 4-diene}$ and $\text{cyclopenta-1, 3-diene}$ are to be drawn.

Concept introduction:

For a molecule that has more than one double bond, the IUPAC name indicates the number of double bonds present as well as their locations. To draw the structure from the given name, first it is important to identify the root. The longest carbon chain or the largest carbon ring containing the all the $\text{C=C}$ groups is the root. The prefixes used in the IUPAC name such as di, tri indicates the number of double bonds in the root. The locator numbers added in the IUPAC name indicate the successive $\text{C=C}$ groups as they are encountered in the root. Immediately before the ‘ene’ suffix, a letter ‘a’ is added followed by the above set of locator numbers. The substituents attached to the root are named in the alphabetical order.