How would the product of cis-stilbene look like after bromination?

1 Answer
Nov 26, 2015

It would probably look like this:

Just as you had started with a molecule with two phenyl substituents on the same side, the product has the configuration on each stereocenter the same as the other (R,R; S,S).

If you rotate the central #"C"-"C"# bond by about #120^@#, you can compare these more closely.

Had you started with (E)-stilbene instead of (Z)-stilbene, you would have gotten meso (1S, 2R) and meso (1R, 2S) isomers instead.

(but ignore the lack of a third arrow in the first step... that part of the image is not correct!)