- #1
silversurf
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Homework Statement
Why would this reaction favor E2 over SN2? Since its a secondary halide reacting with a strong base/nucleophile, and all other conditions being equal isn't SN2 favored? Or is ethoxide somehow a stronger base than nucleophile? If so, how can you tell that it's a better base than nucleophile? Below is the question.
What is the major product formed from the reaction of 2-chlorobutane in aqueous sodium ethoxide?
A.
2-ethoxybutane
B.
1-butene
C.
cis-2-butene
D.
trans-2-butene
Correct Answer
Explanation:
D. 2-Chlorobutane, a secondary alkyl halide, will react with a strong base, such as ethoxide, via an E2 mechanism. Choice A can be eliminated because it is the result of a substitution reaction. Elimination reactions generally follow Zaitsev's rule, which states that the product with the most substituted double bond is formed (provided an unhindered base is used). 1-Butene has a terminal double bond, which is less substituted than the double bond in 2-butene, so choice B can be eliminated. The most stable geometric isomer will have the two largest groups on opposite sides of the double bond, so choice C can be eliminated.