Organic Compounds Containing Halogens Question 204
Question: 2-Bromopentane is heated with potassium ethoxide in ethanol. The major product obtained is
Options:
A) 2-Ethoxypentane
B) Pentene-1
C) cis-Pentene-2
D) trans-Pentene-2
Show Answer
Answer:
Correct Answer: D
Solution:
[d] Potassium ethoxide is a strong base, hence causes elimination reaction. The alkene formed is governed by Saytzeffrule “more substituted an alkene, higher will be its stability”. $ CH_3\overset{Br}{\mathop{\overset{|}{\mathop{C}}}}HCH_2CH_2CH_3\xrightarrow{^{-}OC_2H_5} $
$ CH_2=\underset{Pentene-1}{\mathop{CHCH_2CH_2CH_3}}+CH_3CH $
$ \underset{Pentene-2(morestable)}{\mathop{=CHCH_2CH_3}} $ Further pentene-2 shows geometrical isomerism, cis- and trans- in which trans-isomer having bulkieri groups away from each other is more stable than the cis-isomer.
BETA
