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CBSE Class 12 Chemistry 2020 Outside Delhi Set 1 Solved Paper

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Question : 34 of 37
Marks: +1, -0
Write the product(s) of the following reactions:
OR
(a) Write the mechanism of the following SN1\mathrm{S}_\mathrm{N}1 reaction:
(CH3)3C−Br(CH3)3CAq→⋅NaOH\mathrm{(CH_3)_3C-Br} \overset{\mathrm{Aq} \rightarrow \cdot \mathrm{NaOH}}{\mathrm{(CH_3)_3C}} −OH+NaBr\mathrm{-OH + NaBr}
(b) Write the equation for the preparation of 2-methyl-2-methoxypropane by Williamson synthesis.
Solution:  
OR
(CH3)3C−Br(CH3)3CAq→⋅NaOH\mathrm{(CH_3)_3C-Br} \overset{\mathrm{Aq} \rightarrow \cdot \mathrm{NaOH}}{\mathrm{(CH_3)_3C}} −OH+NaBr\mathrm{-OH + NaBr}
Step-I :
Step-II :
(b) Williamson synthesis:
CH3−CCH3CH3−Br+NaOCH3→\mathrm{CH_3-}\overset{\mathrm{CH_3}}{\underset{\mathrm{CH_3}}{\mathrm{C}}}-\mathrm{Br} + \mathrm{NaOCH_3} \rightarrow CH3−CCH3CH3−O−CH3+NaBr\mathrm{CH_3-}\overset{\mathrm{CH_3}}{\underset{\mathrm{CH_3}}{\mathrm{C}}}-\mathrm{O}-\mathrm{CH_3} + \mathrm{NaBr}
OR
CH3−CCH3CH3−ONa+CH3−BrSodium-2-methyl-2-propoxide→HeatCH3−CCH3CH3−OCH3+NaBr2-methyl-2-methoxy propane\underset{\text{Sodium-2-methyl-2-propoxide}}{\mathrm{CH_3-}\overset{\mathrm{CH_3}}{\underset{\mathrm{CH_3}}{\mathrm{C}}}-\mathrm{ONa} + \mathrm{CH_3-Br}} \xrightarrow{\text{Heat}} \underset{\text{2-methyl-2-methoxy propane}}{\mathrm{CH_3-}\overset{\mathrm{CH_3}}{\underset{\mathrm{CH_3}}{\mathrm{C}}}-\mathrm{OCH_3} + \mathrm{NaBr}} CH3−↙CHC∣3−CH∣3OCH3+NaBr↙2−methyl−2−methoxypropane{{CH}_3- \overset{ {CH}{\overset{\vert}{\mathrm{C}}}_3}↙\underset{ {CH}{|}_3}- {OCH}_3+ {NaBr}}↙{2-methyl-2-methoxy propane}
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