Question

18 multiple choice 2 points provide the proper iupac name for the alkene shown below. ch₃ ch₃ c=c h ch₂ ch(ch₃)₂ (e)-3,5-dimethylhex-2-ene (r)-3,5-dimethylhex-2-ene (s)-3,5-dimethylhex-2-ene (z)-3,5-dimethylhex-2-ene previous

Explanation:

Step1: Determine the priority of substituents

According to the Cahn - Ingold - Prelog (CIP) rules, for the left - hand carbon of the double bond: methyl ($-CH_3$) has higher priority than hydrogen ($-H$). For the right - hand carbon of the double bond: $-CH_2CH(CH_3)_2$ has higher priority than methyl ($-CH_3$) (because of the more substituted carbon in $-CH_2CH(CH_3)_2$).

Step2: Assign the configuration

The higher - priority substituents on the two carbons of the double bond are on the opposite sides. In the E/Z isomerism, when the higher - priority groups are on the opposite sides of the double bond, the configuration is E.

Step3: Name the compound

The parent chain has 6 carbon atoms (hex -), the double bond is at the 2 - position (hex - 2 - ene), and there are two methyl groups at the 3 and 5 positions (3,5 - dimethyl). So the name is (E)-3,5 - dimethylhex - 2 - ene.

Answer:

A. (E)-3,5-dimethylhex-2-ene