JEE Main · 2012 · 29 Apr 2012 · Offline · Aldehydes Ketones and Carboxylic Acids

Iodoform can be prepared from all except :

(A)Ethyl methyl ketone
(B)Isopropyl alcohol
(C)3-Methyl-2-butanone
(D)Isobutyl alcohol✓ Correct

Answer: (D)

Solution

The iodoform test is given by compounds carrying a methyl ketone group,

C H_{3} CO -

, or a

C H_{3} CH (OH) -

group that can be oxidised to one. Ethyl methyl ketone, isopropyl alcohol and 3-methyl-2-butanone each contain such a unit and so respond. Isobutyl alcohol,

(C H_{3})_{2} CHC H_{2} OH

, is a primary alcohol with no

C H_{3} CH (OH) -

grouping, so it is the one that does not give iodoform.

JEE Main · 2012 · 29 Apr 2012 · Offline · Single correct option

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