JEE Advanced 2022 Paper 2, Chemistry Section 1 Q8: Stereoisomerism

Complete reductive ozonolysis cleaves every C=C of P. The cleavages occur at six C=C bonds, generating seven fragments along the chain.

Working through the symmetric structure:

From each terminal $(C{H}_3{)}_{2}C=CH(C{H}_3)$ end one obtains acetaldehyde (CH${}_3$CHO) — achiral.

The fragments adjacent to the chiral C(OH)(CH${}_3$) centers become $\alpha$-hydroxy 1,2-diketone fragments. Two of the resulting fragments are simple symmetric diketo compounds (achiral) and two are $\alpha$-hydroxy ketoaldehyde fragments that retain the stereogenic carbon bearing the OH and CH${}_3$; these are the chiral pieces.

The central fragment from the symmetric middle portion is achiral by internal symmetry.

Counting unique chiral molecules among the products: 2.