Q2 · CSIR NET Chemistry, June 2018
Paper: CSIR NET June 2018 · Subject: Organic Chemistry · Chapter: General Organic Chemistry · Topic: General Organic Chemistry – General · Marks: 2 · Difficulty: Hard
For the following compounds, the correct order of reactivity towards nucleophilic acyl substitution is
(a)acetyl chloride < methyl acetate < acetic anhydride < acetamide
(b)acetamide < methyl acetate < acetic anhydride < acetyl chloride
(c)acetamide < acetic anhydride < acetyl chloride < methyl acetate
(d)methyl acetate < acetamide < acetic anhydride < acetyl chloride
Answer
Answer (as printed): B
Explanation
Leaving group ability affects the reactivity. The electropfhilic character of acetamide is minimum due to +R effect. +R effect is weaker in case of methyl acetate. +R effect is still weaker, acyl group is more electrophilic Weakest +R group, maximum electrophilicity of acyl group. Thus the order is acetamide < methyl acetate < acetic anhydride < acetyl chloride
Explanation as extracted from the printed page; notation may be imperfect.
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