Consider the following compounds 1. `CH_(3)CH_(2)CH_(2)Br " " 2 CH_(2)CHBrCH_(3)` 3. `(CH_(3))_(3)CBr` These compounds are dehydrohalgenated by treate
Consider the following compounds
1. `CH_(3)CH_(2)CH_(2)Br " " 2 CH_(2)CHBrCH_(3)`
3. `(CH_(3))_(3)CBr`
These compounds are dehydrohalgenated by treatement with strong base under indentical condition. The correct sequence of reactivity of these compounds in the given reaction is
A. `1 gt 2 gt 3`
B. `2 gt 1 gt 3`
C. `3 gt 1 gt 2`
D. `3 gt 2 gt 1`
1 Answers
Correct Answer - D
As we proceed along a series of alkyl halide from `1^(@) " to" 2^(@) "to" 3^(@)`, th structure becomes more branched at the carbon carrying the halogen atom. This increases branching has two result.
i. It providees a greater number of `beta`- hydrogenes for attack by base, and hence, a more favorable probability factor towards elimination.
i It leads to more highly branched, more stable alkene. Thereofore, in dehydro halogenation, the increasing order of reactivity of alkyl halides is
`3^(@) gt 2^(@) gt 1^(@) gt or 3 gt 2 gt 1 `