Question

Which of the following correspond $(s)$ has '$Z$' configuration?

• A. (i) only
• B. (ii) only
• C. (iii) only
• D. (i) and (iii)

Answer 1

Answer: (D)

When the groups with higher priority (ie, with high atomic number) are present on same side of double bond, then the configuration is $Z$ but when present on opposite side of double bond, the configuration is $E$. (Priority: $Br>CI$ and $C{H}_3>H$ ) Hence, compound (i) and (iii) have $(Z)$ configuration.