Question

Which of the following products as shown by the dehydrohalogenation of alkyl halides with sodium ethoxide in ethanol is correctly marked as major product?

(i)

(ii) $CH_{3} - \overset{\underset{\overset{Br}{|}}{\underset{CH_{3}}{|}}}{C} - CH_{2}CH_{3}\underset{C_{2}H_{5}OH}{\overset{\quad C_{2}H_{5}ONa\quad}{\rightarrow}}CH_{2} = \underset{\underset{\underset{(Minor)}{CH_{3}}}{|}}{C} - CH_{2}CH_{3} + CH_{3} - \underset{\underset{\underset{(Major)}{CH_{3}}}{|}}{C = CHCH_{3}}$

(iii)

}{+ CH_{3} - \overset{\underset{\overset{CH_{3}}{|}}{\underset{\underset{(Minor)}{CH_{3}}}{|}}}{C} - \overset{\overset{CH_{2}}{||}}{C} - CH_{2} - CH_{3}}$$

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

Answer 1

Answer: (C)

(ii) and (iii)

Answer 2

In (i) is major product while is minor product according to saytzeff’s rule.