Write structures for each of the following compounds. Why are the given names incorrect ? Write correct IUPAC names : (i)2-Ethylpentane , (ii)5-Ethyl-3-methylheptane.

Write structures for each of the following compounds. Why are the give

1.	Write structures for each of the following compounds. Why are the given names incorrect ? Write correct IUPAC names : (i)2-Ethylpentane , (ii)5-Ethyl-3-methylheptane.
Answer» SOLUTION :`(i)CH_3-underset("".^2CH_2overset1CH_3)underset(\|)overset3(CH)-overset4CH_2overset5CH_2overset6CH_3` The longest chain here contains six carbon atoms and not five . Therefore, the correct name is 2-methylhexane. (ii)`overset7CH_3-overset6CH_2-undersetunderset(CH_3)\|overset5CH-overset4CH_2-undersetunderset(""CH-CH_3)\|overset3(CH)-overset2CH_2-overset1CH_3` Since 'e' COMES before 'm' in ALPHABETICAL order , therefore , NUMBERING must be done from right to left. Therefore, the correct name is 3-ethyl-5-methylheptane.