Draw a structure for each alkane.
(a) 2-methylbutane
(b) 3-ethyl-2-methylhexane
(c) 3-isopropylheptane
(d) 2,5-dimethyloctane
Solution 45P :
Step 1:
(a) 2-methylbutane :
‘Butane’ in the name, ‘2-methylbutane’ indicates there are 4 carbon atoms in the longest chain and ‘2-methyl’ indicates there is methyl(-CH3) group on the 2nd carbon atom. Hence the structure for the given alkane is :
(b) 3-ethyl-2-methylhexane :
‘hexane’ in the name, ‘3-ethyl-2-methylhexane’ indicates there are 6 carbon atoms in the longest chain and ‘2-methyl’ indicates there is methyl(-CH3) group on the 2nd carbon atom and ‘3-ethyl’ indicates there is ethyl(-CH2-CH3) group on the 3rd carbon atom. Hence the structure for the given alkane is :
(c) 3-isopropylheptane :
‘heptane’ in the name, ‘3-isopropylheptane’ indicates there are 7 carbon atoms in the longest chain and ‘3-isopropyl’ indicates there is isopropyl(-CHCH3-CH3) group on the 3rd carbon atom. Hence the structure for the given alkane is :
(d) 2,5-dimethyloctane :
‘octane’ in the name, ‘2,5-dimethyloctane’ indicates there are 8 carbon atoms in the longest chain and ‘2,5-dimethyl’ indicates there is methyl(-CH3) group on the 2nd and 5th carbon atom. Hence the structure for the given alkane is :
