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JEE Main 5 April 2024, Shift 1, Chemistry Q79

Question 79 of 90 in this shift, Chemistry question 19 of 30, Section A.

Identify 'A' in the following reaction : butan-2-one (

\mathrm{CH_3-C(=O)-CH_2-CH_3}

)

\xrightarrow[\text{(ii) ethylene glycol/KOH}]{\text{(i) } \mathrm{N_2H_4}}

'A'

The figure, in words

Reactant drawn as skeletal formula: C=O carbonyl carbon with CH3 on one side and CH2-CH3 on the other (butan-2-one). Reagents over the arrow: (i) N2H4, (ii) ethylene glycol/KOH, giving 'A'.

(1) $\mathrm{(CH_3)_2C{=}N{-}NH_2}$ [figure: C bearing two CH3 groups, double bonded to N-NH2]
(2)[figure: butane, CH3-CH2-CH2-CH3 skeletal zigzag with terminal CH3 groups]Official answer
(3) $\mathrm{CH_3(H_5C_2)C{=}N{-}NH_2}$ [figure: C bearing CH3 and $\mathrm{H_5C_2}$ , double bonded to N-NH2]
(4)[figure: butan-2-ol, skeletal zigzag CH3-CH(OH)-CH2-CH3 with OH on the second carbon]

Official answer

Option 2

NTA final key.

Chapter: Aldehydes, Ketones and Carboxylic Acids
Topic: Alkanes and Free Radicals
Idea tested: Wolff-Kishner Reduction to Alkanes

JEE Main 5 April 2024, Shift 1, Chemistry Q79

Same idea in other shifts