Explain the reaction of methoxyethane with concentrated $HI$ and describe its mechanism.
(N/A) Reaction of methoxyethane with concentrated $HI$: When methoxyethane is heated with concentrated $HI$,the $C-O$ bond breaks to form methyl iodide and ethanol. At higher temperatures,ethanol is further converted into ethyl iodide.
$(b)$ Mechanism: This reaction proceeds via an $S_{N}2$ mechanism in the following steps:
Step-$1$: Protonation of the ether occurs due to the presence of acidic $HI$,forming a protonated ether.
Step-$2$: The nucleophilic attack by $I^{-}$ results in the formation of methyl iodide $(CH_{3}I)$ and ethanol $(C_{2}H_{5}OH)$.
$(i)$ The nucleophile $I^{-}$ attacks the smaller alkyl group $(CH_{3})$ of the protonated ether from the opposite side,forming a transition state $(T)$ where the $C-I$ bond is partially formed and the $C-O$ bond is partially broken.
$(ii)$ In the transition state,the bond breaks. Since the rate depends on two species,it is a second-order or bimolecular reaction.
$(iii)$ Since the nucleophile $I^{-}$ displaces the $OCH_{2}CH_{3}$ (ethoxy) group from the ether,the reaction follows a nucleophilic substitution mechanism.
$(b)$ Mechanism: This reaction proceeds via an $S_{N}2$ mechanism in the following steps:
Step-$1$: Protonation of the ether occurs due to the presence of acidic $HI$,forming a protonated ether.
Step-$2$: The nucleophilic attack by $I^{-}$ results in the formation of methyl iodide $(CH_{3}I)$ and ethanol $(C_{2}H_{5}OH)$.
$(i)$ The nucleophile $I^{-}$ attacks the smaller alkyl group $(CH_{3})$ of the protonated ether from the opposite side,forming a transition state $(T)$ where the $C-I$ bond is partially formed and the $C-O$ bond is partially broken.
$(ii)$ In the transition state,the bond breaks. Since the rate depends on two species,it is a second-order or bimolecular reaction.
$(iii)$ Since the nucleophile $I^{-}$ displaces the $OCH_{2}CH_{3}$ (ethoxy) group from the ether,the reaction follows a nucleophilic substitution mechanism.
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Similar Questions
The following are possible syntheses of phenyl propyl ether. Which one would work?
$(i)$ $C_6H_5OH$ $\xrightarrow{KNH_2}$ $\xrightarrow{CH_3CH_2CH_2Br}$
(ii) $CH_3CH_2CH_2OH$ $\xrightarrow{NaOH}$ $\xrightarrow{C_6H_5Br}$
(iii) $CH_3CH_2CH_2OH$ $\xrightarrow{NaH}$ $\xrightarrow{C_6H_5Br}$
$(i)$ $C_6H_5OH$ $\xrightarrow{KNH_2}$ $\xrightarrow{CH_3CH_2CH_2Br}$
(ii) $CH_3CH_2CH_2OH$ $\xrightarrow{NaOH}$ $\xrightarrow{C_6H_5Br}$
(iii) $CH_3CH_2CH_2OH$ $\xrightarrow{NaH}$ $\xrightarrow{C_6H_5Br}$
Medium
View SolutionGiven below are two statements: one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R).$
Assertion $(A):$ Synthesis of ethyl phenyl ether may be achieved by Williamson synthesis.
Reason $(R):$ Reaction of bromobenzene with sodium ethoxide yields ethyl phenyl ether.
In the light of the above statements,choose the most appropriate answer from the options given below:
Assertion $(A):$ Synthesis of ethyl phenyl ether may be achieved by Williamson synthesis.
Reason $(R):$ Reaction of bromobenzene with sodium ethoxide yields ethyl phenyl ether.
In the light of the above statements,choose the most appropriate answer from the options given below:
Give the common and $\rm {IUPAC}$ names for the following ether compounds:
$(i) \ CH_3OCH_3$
$(ii) \ C_2H_5OC_2H_5$
$(iii) \ C_6H_5OC_6H_5$
$(iv) \ CH_3OCH_2CH_2CH_3$
$(v) \ CH_3OCH(CH_3)_2$
$(vi) \ C_6H_5OCH_3$
$(vii) \ C_6H_5OCH_2CH_3$
$(viii) \ C_6H_5O(CH_2)_6CH_3$
$(ix) \ C_6H_5OCH_2CH_2CH(CH_3)_2$
$(x) \ CH_3OCH_2CH_2OCH_3$
$(xi) \ C_2H_5OCH_2CH_2OC_2H_5$
$(xii) \ CH_3OCH_2CH_2CH_2OCH_3$
$(xiii) \ CH_3OCH_2CH_2OC_2H_5$
$(xiv) \ \text{Cyclohexyl methyl ether}$
$(i) \ CH_3OCH_3$
$(ii) \ C_2H_5OC_2H_5$
$(iii) \ C_6H_5OC_6H_5$
$(iv) \ CH_3OCH_2CH_2CH_3$
$(v) \ CH_3OCH(CH_3)_2$
$(vi) \ C_6H_5OCH_3$
$(vii) \ C_6H_5OCH_2CH_3$
$(viii) \ C_6H_5O(CH_2)_6CH_3$
$(ix) \ C_6H_5OCH_2CH_2CH(CH_3)_2$
$(x) \ CH_3OCH_2CH_2OCH_3$
$(xi) \ C_2H_5OCH_2CH_2OC_2H_5$
$(xii) \ CH_3OCH_2CH_2CH_2OCH_3$
$(xiii) \ CH_3OCH_2CH_2OC_2H_5$
$(xiv) \ \text{Cyclohexyl methyl ether}$
Medium
View SolutionIdentify $A$ and $B$ in the following reaction: $C_6H_5CH_2-O-C_6H_5 + HI \rightarrow A + B$
Which of the following compounds on boiling with $KMnO_4$ (alk.) and subsequent acidification will not give benzoic acid?
Medium
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