are named using the prefix cyclo and considering the —OH group attached to C– . Cyclohexanol -Methylcyclopentanol (b) Phenols: The simplest hydroxy derivative of benzene is phenol. It is its common name and also an accepted IUPAC name. As structure of phenol involves a benzene ring, in its substituted compounds the terms ortho ( , - disubstituted), meta ( , -disubstituted) and para ( , -disubstituted) are often used in the common names.
Common name Phenol o -Cresol m -Cresol p -Cresol IUPAC name Phenol -Methylphenol -Methylphenol -Methylphenol Dihydroxy derivatives of benzene are known as , -, , - and , -benzenediol. Common name Catechol Benzene- diol , - Resorcinol Benzene- diol , - Hydroquinone or quinol Benzene- diol , - IUPAC name (c) Ethers: Common names of ethers are derived from the names of alkyl/ aryl groups written as separate words in alphabetical order and adding the word ‘ ether ’ at the end. For example, CH OC H is ethylmethyl ether. Table .
: Common and IUPAC Names of Some Ethers Compound Common name IUPAC name CH OCH Dimethyl ether Methoxymethane C H OC H Diethyl ether Ethoxyethane CH OCH CH CH Methyl n-propyl ether -Methoxypropane C H OCH Methyl phenyl ether Methoxybenzene (Anisole) (Anisole) C H OCH CH Ethyl phenyl ether Ethoxybenzene (Phenetole) C H O(CH ) – CH Heptyl phenyl ether -Phenoxyheptane CH O Methyl isopropyl ether -Methoxypropane Phenyl isopentyl ether - Methylbutoxybenzene CH – O – CH – CH – OCH — , -Dimethoxyethane — -Ethoxy- - , -dimethylcyclohexane If both the alkyl groups are the same, the prefix ‘di’ is added before the alkyl group. For example, C H O C H is diethyl ether. According to IUPAC system of nomenclature, ethers are regarded as hydrocarbon derivatives in which a hydrogen atom is replaced by an – OR or – OAr group, where R and Ar represent alkyl and aryl groups, respectively. The larger (R) group is chosen as the parent hydrocarbon.