Question

$(C{H}_3{)}_{2}CH-CH=CH-CH=CH-\underset{C_2{H}_5}{\underset{|}{C}H}-C{H}_3$

The IUPAC name of this is:

• A. $2,7-dimethyl-3,5-nonadiene$
• B. $2,7-dimethyl-2-methylbutadiene$
• C. $2-methyl-7-ethyl-3,5-octadiene$
• D. $1,1-dimethyl-6-ethyl-2,4-heptadiene$

Answer 1

The correct option is A $2,7-dimethyl-3,5-nonadiene$

1) Consider the longest chain and that chain should have the two double bonds. So, the parent chain has 9 carbons.

2) Assign numbers such that the sum of the numbers of the double bonds must be least.

3) At the second and the seventh positions, methyl groups are there.

4) So, IUPAC name is $2,7-dimethyl-3,5-nonadiene.$