. Nomenclature (a) Alcohols: The common name of an alcohol is derived from the common name of the alkyl group and adding the word alcohol to it. For example, CH OH is methyl alcohol. .
. Phenols— Mono, Di and trihydric phenols Ethers are classified as simple or symmetrical , if the alkyl or aryl groups attached to the oxygen atom are the same, and mixed or unsymmetrical , if the two groups are different. Diethyl ether, C H O C H , is a symmetrical ether whereas C H O CH and C H O C H are unsymmetrical ethers. Monohydric According to IUPAC system, the name of an alcohol is derived from the name of the alkane from which the alcohol is derived, by substituting ‘ e ’ of alkane with the suffix ‘ ol ’.
The position of substituents are indicated by numerals. For this, the longest carbon chain (parent chain) is numbered starting at the end nearest to the hydroxyl group. The positions of the –OH group and other substituents are indicated by using the numbers of carbon atoms to which these are attached. For naming polyhydric alcohols, the ‘e’ of alkane is retained and the ending ‘ol’ is added.
The number of – OH groups is indicated by adding the multiplicative prefix, di, tri, etc., before ‘ol’. The positions of – OH groups are indicated by appropriate locants, e.g., HO–CH –CH –OH is named as ethane– , -diol. Table . gives common and IUPAC names of a few alcohols as examples.
Table . : Common and IUPAC Names of Some Alcohols CH – OH Methyl alcohol Methanol CH – CH – CH – OH n -Propyl alcohol Propan- -ol Isopropyl alcohol Propan- -ol CH – CH – CH – CH – OH n -Butyl alcohol Butan- -ol sec -Butyl alcohol Butan- -ol Isobutyl alcohol -Methylpropan- -ol tert -Butyl alcohol -Methylpropan- -ol HO–H C–CH –OH Ethylene glycol Ethane- , -diol Glycerol Propane - , , -triol Compound Common name IUPAC name Cyclic alcohols