Alcohols Phenols And Ethers Question 86
Question: tert-Butyl ethyl ether can’t be prepared by which reaction-
Options:
A) tert- Butanol + ethanol $ \xrightarrow{{H^{+}}} $
B) tert-Butyl bromide + sodium ethoxide $ \to $
C) Sodium tert-butoxide + ethyl bromide $ \to $
D) Isobutene + ethanol $ \xrightarrow{{H^{+}}} $
Show Answer
Answer:
Correct Answer: B
Solution:
[b] $ {{(CH_3)}_3}CBr+NaOC_2H_5 $ can’t be applied for synthesising the ether because sod. ethoxide, being a strong base, will preferentially cause elimination reaction. $ {{( CH_3 )}_3}CBr\xrightarrow{-OC_2H_5}{{( CH_3 )}_2}C=CH_2+HBr $ In isobutene + ethanol, isobutene will form tert-butyl cation which reacts with ethanol, a nucleophile to form ether. $ {{(CH_3)}_2}C=CH_2\xrightarrow{{H^{+}}}{{(CH_3)}_2}\overset{+}{\mathop{C}}CH_3 $
$ \xrightarrow[(ii)-{H^{+}}]{(i)CH_3CH_2OH}{{(CH_3)}_3}COCH_2CH_3 $
BETA
