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प्रश्न
Explain the following reactions:
Stephan reaction
उत्तर
This reaction is used to synthesize aldehydes from nitriles or cyanides. Firstly, nitriles or cyanides are reduced in presence of stannous chloride and hydrochloric acid in ethyl acetate solvent to form imine intermediate. Then hydrolysis of this intermediate with water gives the corresponding aldehyde.
\[\ce{CH3 - C ≡ N + 2[H] ->[SnCl2/HCl][Ether] CH3 - CH = NH + HCl ->[H2O/H^+] \underset{Acetaldehyde}{CH3CHO} + NH4Cl}\]
APPEARS IN
संबंधित प्रश्न
Write the product in the following reaction
Write the product in the following reaction:
How will you prepare the given compound from benzene? You may use any inorganic reagent and any organic reagent having not more than one carbon atom.
p-Nitrobenzaldehyde
Aldehydes are produced on reduction of the following by DIBAL-H:
Match the common names given in Column I with the IUPAC names given in Column II.
| Column I (Common names) |
Column II (IUPAC names) |
||
| (i) | Cinnamaldehyde | (a) | Pentanal |
| (ii) | Acetophenone | (b) | Prop-2-enal |
| (iii) | Valeraldehyde | (c) | 4-Methylpent-3-en-2-one |
| (iv) | Acrolein | (d) | 3-Phenylprop-2-enal |
| (v) | Mesityl oxide | (e) | 1-Phenylethanone |
Match the example given in Column I with the name of the reaction in Column II.
| Column I (Example) |
Column II (Reaction) |
||
| (i) | \[\begin{array}{cc} \phantom{...}\ce{O}\phantom{..............................}\ce{O}\phantom{}\\ \phantom{...}||\phantom{..............................}||\phantom{}\\ \ce{CH3 - C - Cl + H2 ->[Pd - C/BasO4] CH3 - C - H} \end{array}\] |
(a) | Friedel Crafts acylation |
| (ii) |  |
(b) | HVZ reaction |
| (iii) |  |
(c) | Aldol condensation |
| (iv) | \[\begin{array}{cc} \ce{R - CH2 - COOH ->[Br/Red P] R - CH - COOH}\\ \phantom{.....................}|\\ \phantom{.......................}\ce{Br} \end{array}\] |
(d) | Cannizaro’s reaction |
| (v) | \[\ce{CH3 - CN ->[(i) SnCl2/HCl][(ii) H2O/H+] CH3CHO}\] | (e) | Rosenmund’s reductio |
| (vi) | \[\ce{2CH3CHO ->[NaOH] CH3 - CH = CHCHO}\] | (f) | Stephen’s reaction |
\[\begin{array}{cc}
\ce{CH3 - CH2 - CH - CH3}\\
\phantom{.....}|\\
\phantom{......}\ce{Cl}
\end{array}\] obtained by chlorination of n-butane, will be
Benz aldehyde + NaOH →
Convert the following:
Benzoic acid to Benzaldehyde
Write the name of the reaction, structure and IUPAC name of the product formed when:
CH3CH2CN reacts with stannous chloride in the presence of hydrochloric acid, followed by hydrolysis.
