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प्रश्न
What is meant by the following term? Give an example of the reaction in the following case.
Oxime
उत्तर
Oximes are formed by reaction between aldehydes or ketones and hydroxylamine. The reaction is carried out in a mildly acidic condition.
\[\begin{array}{cc}
\ce{H3C}\phantom{...........................}\ce{H3C}\phantom{.....................}\\
\backslash\phantom{..............................}\backslash\phantom{................}\\
\ce{= O + \underset{Hydroxylarnine}{H2N-OH} ->[pH 3.5] \phantom{......}= NOH + H2O}\\
/\phantom{..............................}/\phantom{.................}\\
\ce{H}\phantom{............................}\ce{\underset{Oxime}{H}}\phantom{..................}
\end{array}\]
APPEARS IN
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| The carbon-oxygen double bond is polarised in aldehydes and ketones due to higher electronegativity of oxygen relative to carbon. Therefore, they undergo nucleophilic addition reactions with a number of nucleophiles such as HCN, NaHSO3, alcohols, ammonia derivatives and Grignard reagents. Aldehydes are easily oxidised by mild oxidising agents as compared to ketones. The carbonyl group of carboxylic acid does not give reactions of aldehydes and ketones. Carboxylic acids are considerably more acidic than alcohols and most of simple phenols. |
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CH3CHO, \[\begin{array}{cc}
\ce{(CH3)3C-C-CH3}\\
\phantom{....}||\\
\phantom{....}\ce{O}
\end{array}\], \[\begin{array}{cc}
\ce{CH3-C-CH3}\\
||\\
\ce{O}
\end{array}\]
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OR
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| (i) |  |
| (ii) |  |
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