Which one of the following molecules does NOT exist as a meso isomer?

Question

Vimal Swarnkar · Accepted Answer

(d) 2,5-Dibromohexane (both Br wedged). Meso needs two (or more) stereocentres with internal mirror symmetry. 2,3,4-Tribromopentane (a, b) and 2,5-dibromohexane drawn (c) are meso forms. (d) 2,5-dibromohexane with both Br wedged in this zigzag is the (R,R)/(S,S) form → chiral, no meso → (d).

Answer

(a) 2,3,4-Tribromopentane (Br wedge, dash, wedge)

Answer

(b) 2,3,4-Tribromopentane (all three Br wedged)

Answer

(c) 2,5-Dibromohexane (one Br wedge, one dash)

Geo-Scientist Prelims 2020 Chemistry Q88: Which one of the following molecules does NOT exist as a meso isomer?

QuestionStereochemistry / meso compounds