Question

why is the answer C? Wouldn't 5 be meso? please explain each answer if you can

BE 60 Which of the following are optically active compounds? CH3 H Br H2H HCH, H- CHg Br CH3 H H CH₃ CH3 H H H Br Br Br Br 3 CH₂ Br A. 1 and 4 B. 1,4, and 5 C. 2,3, and 5 D. 4 only

Answer 1

(30) 2) In fischer Projection at each chiral center formula even number of interchange gives homoner. - CM₂ CH3 Cha nta Br ont Bront Br in 162 n Bryn Meso at c-o interchange ait (2 - 2 interchange So A 2B are identical In B molecule have two chiral center and have a Plane of Symmetry between two chiral Center So ① is meso compound and optically inactive. Mexo compounds areoptically inactive due to Internal compansation. - Br Achiral so - — Сиз optically active molecule. и or Chiral Center All the groups and different n a Bor ons L interchanse Linter H C nc atla n t n ® IS cha obrically inactive. ③ 2 A are not identical Br isoptically at C-0 interchange at C2-l interchange active

63 n Achired becauxe a Chy group at same carbon -CM3 Cha cha n In Br 2 H at some Carbon so achiral. optically inactive have no chical Center So ® is a Ch3 cha ch, - Bron B th Brth o tinterchange at C2 . meso o n are not idenheal sooptically inactive e A 2 B obticall e tical active So molecule 2, 3, 2s are optically active obtion © 2,325 is correct :