blacky last edited by
ANSWER IS ACD
Gunjan Mehta last edited by
@blacky P will be formed with the help of NGP of phenyl and retention of configuration will be observed at 2nd carbon
Whereas Q will be formed due to SN2 which will result in inversion of configuration at 2nd carbon
So PandQ should be diastereomers .
And R and S will be same because they are formed by SN2