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प्रश्न
Illustrate with examples the limitations of Williamson synthesis for the preparation of certain types of ethers.
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उत्तर
The main limitation of Williamson's ether synthesis is that it cannot be used to prepare unsymmetrical ethers where the compound has tertiary or secondary alkyl groups. For example, a reaction between tert-butyl bromide and sodium methoxide yields an alkene.
\[\begin{array}{cc}
\ce{CH3}\phantom{..........................}\ce{CH2}\phantom{.........}\\
\phantom{.}|\phantom{..............................}||\phantom{............}\\
\ce{CH3 - C - Br + NaOCH3 -> CH3 - C + NaBr + CH3OH}\\
|\phantom{..............................}|\phantom{............}\\
\ce{\underset{tert-Butylbromide}{CH3}\phantom{..................}\ce{\underset{2-Methylpropene}{CH3}}}\phantom{..........}\
\end{array}\]
This is due to the formation of alkene and the dominance of the competing elimination reaction over SN2.
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संबंधित प्रश्न
Explain the mechanism of the following reaction:
How do you convert the following :
Phenol to anisole
Write the reactions of Williamson synthesis of 2-ethoxy-3-methylpentane starting from ethanol and 3-methylpentan-2-ol.
\[\ce{(CH3)3CONa + CH3CH2Cl ->[-NaCl] (CH3)3COC2H5}\] is called:
Explain why low molecular mass alcohols are soluble in water.
Identify the following named reaction
\[\ce{C2H5Br ->[NaOCH3] C2H5OCH3}\]
Which of the following compounds gives a secondary alcohol upon reaction with methylmagnesium bromide?
Name the suitable alcohol and reagent, from which 2-Chloro-2-methyl propane can be prepared.
Williamson's synthesis of ether is an example of ______.
HBr reacts with \[\ce{CH2 = CH - OCH3}\] under anhydrous conditions at room temperature to give ______.
Which of the following reactions are feasible?
Write the name of reagent and equation for the preparation of the following ethers by Williamson’s synthesis:
2-Methoxy-2-methylpropane
Write the name of the reagent and equation for the preparation of the following ether by Williamson’s synthesis:
2-Methoxy-2-methylpropane
Write the name of reagent and equation for the preparation of the following ethers by Williamson’s synthesis:
2-Methoxy-2-methylpropane
Identify the product(s) is/are formed when 1-methoxy propane is heated with excess HI. Name the mechanism involved in the reaction.
Predict the major product, when 2-methyl but -2-ene is converted into an alcohol in the following method.
Acid catalysed hydration
What will be the product (X and A)for the following reaction
\[\ce{acetylchloride->[i)CH3MgBr][ii)H3O+]X ->[acidk2crp3]A}\]
Short Answer Question.
Identify the product (s) is / are formed when 1 – methoxy propane is heated with excess HI. Name the mechanism involved in the reaction
Write the name of reagent and equation for the preparation of the following ethers by Williamson’s synthesis:
2-Methoxy-2-methylpropane
