question_answer

Which of the following applies in the reaction? \[C{{H}_{3}}CHBrC{{H}_{2}}C{{H}_{3}}\xrightarrow[{}]{Alco.\,KOH}?\] (I)\[C{{H}_{2}}CH=CHC{{H}_{3}}\](major product) (II) \[C{{H}_{2}}=CHC{{H}_{2}}C{{H}_{3}}\] (minor product)

A)  Hofmanns rule   

B)  Saytzeffs rule

C)  Kharasch effect  

D)  Markownikoffs rule

Correct Answer: B

Solution :

 \[C{{H}_{3}}\underset{\begin{smallmatrix}  | \\  Br \end{smallmatrix}}{\mathop{CH}}\,C{{H}_{2}}C{{H}_{3}}\] This reaction is governed by Saytzeffs rule. .According to this rule, the elimination of\[\beta -\]hydrogen atom take place from the carbon having the less number of H-atoms or in other words, a stable alkene is formed (More substituted alkene is more stable)