Assign priority numbers to the following groups :
(a) -Cl -CH₃ -OH -CH₂CH₃
(b) -NH₂ -COOH -Br -H
(c) -I -SCH₃ -OCH₃ -CH₃
(d) -CH₂Cl -CHCl₂ -CH₂Br -CCl₃

Question

Assign priority numbers to the following groups : (a) -Cl -CH 3 -OH -CH 2 CH 3 (b) -NH 2 -COOH -Br -H (c) -I -SCH 3 -OCH 3 -CH 3 (d) -CH 2 Cl -CHCl 2 -CH 2 Br -CCl 3

TestHub · Accepted Answer

Compare the atoms directly attached to the stereocenter first, then move outward to the first point of difference.

(a) Cl (17) $>$ O (8) $>$ C (6) : Cl = 1, OH = 2. CH₂CH₃ : (C, H, H) beats CH₃ : (H, H, H), so CH₂CH₃ = 3, CH₃ = 4.

(b) Br (35) = 1. N (7) $>$ C (6), so NH₂ = 2, COOH = 3, H = 4.

(c) I (53) $>$ S (16) $>$ O (8) $>$ C (6) : I = 1, SCH₃ = 2, OCH₃ = 3, CH₃ = 4.

(d) All first atoms are C. CCl₃ : (Cl, Cl, Cl); CHCl₂ : (Cl, Cl, H); CH₂Br : (Br, H, H); CH₂Cl : (Cl, H, H). So CCl₃ = 1, CHCl₂ = 2, CH₂Br = 3, CH₂Cl = 4.

Ans. (a) Cl = 1, OH = 2, CH₂CH₃ = 3, CH₃ = 4 (b) Br = 1, NH₂ = 2, COOH = 3, H = 4 (c) I = 1, SCH₃ = 2, OCH₃ = 3, CH₃ = 4 (d) CCl₃ = 1, CHCl₂ = 2, CH₂Br = 3, CH₂Cl = 4

Chemistry - STEREO ISOMERISM Question with Solution | TestHub

Options:

Doubts & Discussion