Hi, I have a question from MI 2014 prelim P1 Q24
Why are there only 2 optical isomers for R? Is it due to
internal plane of symmetry? I counted a total of 4 chiral carbons
in R. Did I do additional counting??
There are only 2 chiral C atoms. But due to an internal plane of
symmetry, the R,S and S,R stereoisomers are the meso isomer and
thus optically inactive, and hence the only 2 enantiomeric optical
isomers are S,S and R,R.