Advertisements
Advertisements
प्रश्न
Through which of the following reactions number of carbon atoms can be increased in the chain?
(i) Grignard reaction
(ii) Cannizaro’s reaction
(iii) Aldol condensation
(iv) HVZ reaction
Advertisements
उत्तर
(i) Grignard reaction
(iii) Aldol condensation
Explanation:
Grignard reagent is used to add number of carbon atom in chain.
\[\begin{array}{cc}
\phantom{....................}\ce{R'}\\
\phantom{...................}|\\
\ce{RCHO + R'MgX ->[H2O] R - CH - OH}
\end{array}\]
Aldol condensation involves condensation of aldehydes and ketones with α-hydrogen.
\[\begin{array}{cc}
\ce{CH3CHO ->[dil NaOH] CH3CHCH2CHO ->[Δ][-H2O] CH3CH = CHCHO}\\
|\phantom{..............}\\
\ce{\underset{Aldol}{OH}\phantom{............}}\\
\end{array}\]
APPEARS IN
संबंधित प्रश्न
On acid hydrolysis, propane nitrile gives.
Predict the products of the following reactions:
Show how the following compound can be converted to benzoic acid.
Ethylbenzene
Show how the following compound can be converted to benzoic acid.
Phenylethene (Styrene)
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.
Methyl benzoate
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.
Phenylacetic acid
How will you bring about the following conversion in not more than two steps?
Benazaldehyde to α-Hydroxyphenylacetic acid
How is methoxy benzene prepared from carbolic acid?
Name the reagents used in the following reactions:
Which is the most suitable reagent for the following conversion?
\[\begin{array}{cc}
\phantom{....................}\ce{O}\phantom{.....................................}\ce{O}\phantom{.}\\
\phantom{....................}||\phantom{......................................}||\phantom{.}\\
\phantom{}\ce{CH3 - CH = CH - CH2 - C - CH3 -> CH3 - CH = CH - CH2 - C - OH}\phantom{.}
\end{array}\]
Assertion: Aldehydes and ketones, both react with Tollen’s reagent to form silver mirror.
Reason: Both, aldehydes and ketones contain a carbonyl group.
Match List - I with List - II.
| List - I | List - II | ||
| (a) |  \[\ce{->[CO,HCl][Anhyd. AlCl3/CuCl]}\] |
(i) | Hell-Volhard-Zelinsky reaction |
| (b) |
\[\begin{array}{cc}
\ce{O}\phantom{.................}\\ ||\phantom{.................}\\ \ce{R - C - CH3 + NaOX ->} \end{array}\] |
(ii) | Gattermann-Koch reaction |
| (c) | \[\ce{R - CH2 - OH + R'COOH ->[Conc. H2SO4]}\] | (iii) | Haloform reaction |
| (d) | \[\ce{R - CH2COOH ->[(i) X2/Red P][(ii) H2O]}\] | (iv) | Esterification |
Choose the correct answer from the options given below.
Y is:
Alkaline hydrolysis of C4H8Cl2 gives a compound (A) which on heating with NaOH and I2 produces a yellow precipitate of CHI3. The compound (A) should be ______.
A compound 'X' with molecular formula C3H8O can be oxidised to a compound 'Y' with the molecular formula C3H6O2 'X' is most likely to be ______.
Hex-4-ene-2-ol on treatment with PCC gives 'A'. 'A' on reaction with sodium hypoiodite gives 'B', which on further heating with soda lime gives 'C. The compound 'C' is ______.
Fill in the blanks by choosing the appropriate words from those given in the brackets:
[stable, low, aldehyde, unstable, 6, 4, ethane, Clemmensen’s, 2, 3, carboxylic acid, high, propane, Rosenmund's]
The primary alcohols are easily oxidised first into ______ and then into ______.
