Chemistry - STEREO ISOMERISM Question with Solution | TestHub

Ans. (A) (c), (d), (e), (f) and (g).

Sol. (a) cis-1,2-dimethylcyclobutane and (b) cis-1,3-dimethylcyclobutane each have a plane of symmetry : optically inactive.

(c) trans-1,2-dimethylcyclobutane and (d) trans-1,3-dimethylcyclobutane have no symmetry element : optically active.

(e) 1-chloro-2,3-dimethylcyclobutane, (f) 1-chloro-2,3,4-trimethylcyclobutane and (g) cis-1-chloro-2-methylcyclobutane contain unlike substituents, so no symmetry is possible : optically active.

(h) 2,4-dichloro-1,3-dimethylcyclobutane has a plane of symmetry through the two methyl-bearing carbons : optically inactive.