Question 14.1: Name the following alcohols, utilizing IUPAC nomenclature ru......
Name the following alcohols, utilizing IUPAC nomenclature rules.
a. The longest carbon chain that contains the alcohol functional group has six carbons. When we change the -e to -ol, hexane becomes hexanol. Numbering the chain from the end nearest the —OH group identifi es carbon number 3 as the location of both the —OH group and a methyl group. The complete name is 3-methyl-3-hexanol.
\quad\quad\quad\quad\quad\quad \ \ CH_{3} \\ \overset{1}{C}H_{3}-\overset{2}{C}H_{2}-\overset{3|}{\underset{|}{C}} -\overset{4}{C}H_{2}-\overset{5}{C}H_{2}-\overset{6}{C}H_{3}\\ \quad\quad\quad\quad\quad\quad \ \ OHb. The longest carbon chain containing the —OH group has four carbon atoms. It is numbered from the end closest to the —OH group as follows:
The base name is 1-butanol. The complete name is 2-ethyl-1-butanol.
c. This alcohol is a cyclohexanol. The carbon to which the —OH group is attached is assigned the number 1. The complete name for this alcohol is 3,4- dimethylcyclohexanol. Note that the number 1 is not part of the name.
d. This alcohol is a dimethylheptanol. Numbering from right to left, the location of the hydroxyl group is 1, and locants for the methyl groups are 3 and 4. The complete IUPAC name is 3,4-dimethyl-1-heptanol.
In the naming of alcohols with unsaturated carbon chains, two endings are needed: one for the double or triple bond and one for the hydroxyl group. The -ol suffix always comes last in the name; that is, unsaturated alcohols are named as alkenols or alkynols.
\underset{ \quad\quad {2-Propen-1-ol} \\ {(common name: allyl alcohol)}}{\overset{3}{C}H_{2}=\overset{2}{C}H-\overset{1}{C}H_{2}-OH}The contrast between IUPAC and common names for alcohols is as follows:
IUPAC (one word)
\boxed{alkanol}ethanol
Common (two words)
\boxed{alkyl alcohol}
ethyl alcohol