i. Cyanohydrin ii. Acetal iii. Semicarbazone iv. Aldol v. Hemiacetal vi. Oxime

Question

What is meant by the following terms? Give an example of the reaction in each case.
i. Cyanohydrin ii. Acetal iii. Semicarbazone
iv. Aldol v. Hemiacetal vi. Oxime
vii. Ketal viii. Imine ix. 2,4-DNP-derivative
x. Schiff’s base

Answer 1

i. Cyanohydrin: It is a compound in which cyano and hydroxyl groups are present on same carbon atom.

ii. Acetal: It contains two alkoxy groups, one alkyl group and one H atom on the same carbon atom.

iii. Semicarbazone: It is the condensation product of an aldehyde or ketone with semicarbazide.

iv. Aldol: It is β hydroxy aldehyde or ketone obtained by the condensation of two aldehyde or ketone molecules in presence of a dilute alkali.

v. Hemiacetal: It contains one hydroxyl and one alkoxy group on the same carbon atom.

vi. Oxime: It is the condensation product of an aldehyde or ketone with hydroxyl amine.

vii. Ketal: It contains two alkoxy groups and two alkyl groups on the same carbon atom.

viii. Imine: It contains   group.
It is the condensation product of aldehydes and ketones with ammonia derivatives

ix. 2,4-DNP derivative:
Also known as 2,4-dinitro phenyl hydrazone, it is condensation product of an aldehyde or ketone with 2,4-dinitro phenyl hydrazine (2,4-DNP).

x. Schiff’s base: It is azomethine obtained by the condensation of aldehydes and ketones with primary amines.