JEE Main 2022 · 29 Jul · Shift 2 · Chemistry Q74

← JEE Main 2022 · 29 Jul · Shift 2

ChemistrySingle correct+4 / -1Question 74 of 90

Compound 'A' undergoes following sequence of reactions to give compound 'B'. The correct structure and chirality of compound 'B' is

[where Et is −C $_2$ H $_5$ ]

Compound 'A' (2-bromo-3-methylbutane) is treated with (i) Mg, Et $_2$ O (ii) D $_2$ O to give B.

Compound 'A', 2-bromo-3-methylbutane, converted by (i) Mg, Et2O (ii) D2O into B.

(CH₃)₂CH-CHD-CH₃, Achiral

Option A: 2-deuterio-3-methylbutane, labelled achiral.

(CH₃)₂CH-CH(OD)-CH₃, Chiral

Option B: 3-methylbutan-2-ol-O-d, labelled chiral.

(CH₃)₂CH-CHD-CH₃, Chiral

Option C: 2-deuterio-3-methylbutane, labelled chiral.

(CH₃)₂CH-CH₂-CH₂-OD, Achiral

Option D: 3-methylbutan-1-ol-O-d, labelled achiral.

Answer and worked solution

Official answer: C

Grignard then D₂O replaces Br by D: $\mathrm{(CH_3)_2CH{-}CHD{-}CH_3}$ . C-2 carries H, D, CH₃ and isopropyl, four different groups, so B is chiral.

(C)

Topics:SN1 and SN2 Optical isomerism and chirality

← Previous question Next question →

JEE Main 2022 · 29 Jul · Shift 2, Chemistry question 74