Question 3.15: Writing Structural Formulas from the Names of Organic Compou......

Analyze

First, identify the number of carbon atoms in the chain, and then determine the type and position of the functional group, if any.

Solve

(a) The word stem but- indicates a structure with a four-carbon chain, and the suffix -ane indicates an alkane.
No functional groups are indicated; hence, the condensed structural formula is $CH_{3}(CH_{2})_{2}CH_{3}$.
(b) The -oic ending indicates that the end carbon atom of the four-carbon chain is part of a carboxylic acid group. The condensed structural formula is $CH_{3}(CH_{2})_{2}CO_{2}H$.
(c) The prefix chloro- indicates the substitution of a chlorine atom for a H atom, and the 1- designates that it is on the first C atom of the carbon chain. The carbon chain is five C atoms long, as signified by the word stem pent-. The condensed structural formula is $CH_{3}(CH_{2})_{3}CH_{2}Cl$.
(d) The suffix -ol indicates the presence of a hydroxyl group in place of a H atom, and the 1 designates that it is on the first C atom of the carbon chain. The word stem hex- signifies that the carbon chain is six C atoms long. The condensed structural formula is $CH_{3}(CH_{2})_{4}CH_{2}OH$.

Assess

In summary, to obtain a structural formula from the name, we split the name into its component pieces: stem, prefix, and suffix. All three components provide information about the structure of the molecule.