Advertisements
Advertisements
प्रश्न
Write a note on Stephen reaction.
Advertisements
उत्तर
Nitriles are reduced to imine hydrochloride by stannous chloride in presence of hydrochloric acid which on acid hydrolysis give corresponding aldehydes. This reaction is called Stephen reaction.
\[\ce{\underset{(Alkane nitrile)}{R - C ≡ N +}2[H] ->[SnCl2, HCl]\underset{(Imine hydrochloride)}{R - HC = NH.HCl}->[H3O+]\underset{(Aldehyde)}{R - CHO} + NH4Cl}\]
e.g. \[\ce{\underset{(Ethanenitrile)}{H3C - C ≡ N}+2[H] ->[SnCl2, HCl][(reduction)]\underset{(Ethanimine hydrochloride)}{CH3 - HC = NH.HCl}->[H3O+]\underset{(Ethanal)}{CH3 - CHO} + NH4Cl}\]
संबंधित प्रश्न
Write another name of disproportionation reaction?
ln which of the following reactions, both oxidised and reduced forms of the same compound are obtained?
Which of the following compounds does NOT undergo aldol condensation?
Acetone on Clemmensen reduction gives ____________.
The number of α-H atoms in butanal is ____________.
\[\ce{CH2 = CH2 ->[i) O3][ii) Zn/H2O] X ->[NH3] Y}\] ‘Y’ is:
Which of the following represents the correct order of acidity in the given compounds.
Identify A, B and C.
How will you convert benzaldehyde into the following compound?
Benzoic acid
How will you convert benzaldehyde into the following compound?
α-hydroxy phenyl acetic acid
Write the structure of the major product of the aldol condensation of benzaldehyde with acetone.
How will you prepare acetamide from methyl cyanide?
How will you prepare lactic acid from ethanol?
How will you prepare acetaldehyde from ethyne?
Which one of the following substituents at para-position is most effective in stabilizing the phenoxide 
ion?
Which of the following compound will give positive iodoform test?
Which of the following reaction does not involve either oxidation or reduction?
What is the number of different products formed when mixture of ethanal and propanal reacts with aq. NaOH after warming?
Which of the following compounds does not undergo a haloform reaction?
Which of the following is not correctly matched?
Aldehydes are readily oxidised to yield carboxylic acids but ketones are inert to oxidation. Which is the most likely explanation regarding this difference in reactivity?
Write the structure of the major product of the aldol condensation of benzaldehyde with acetone.
Write the structure of the major product of the aldol condensation of benzaldehyde with acetone.
Write the structure of the major product of the aldol condensation of benzaldehyde with acetone.
How will you prepare Acetic anhydride from acetic acid ?
Write the structure of the major product of the aldol condensation of benzaldehyde with acetone.
How will you prepare Acetic anhydride from acetic acid.
How will you prepare Acetic anhydride from acetic acid.
