Question

How many stereoisomer of product (P) is possible ?

Answer 1

It has $4$ chiral center and symmetry.
No. of stereoisomer $=2^{(n-1)}+2^{(\frac{n}{2}-1)}$
$=2^{(4-1)}+2^{(\frac{4}{2}-1)}$
$=8+2=10$