Which of the eight structures shown below are chiral?

A

Identify $($with an asterisk, ${?}^{**})$ all of the stereogenic centers of the developmental anti$-$depressant drug

Samidornhan $($shown below$).$ How many stereoisomers are possible?

Number of possible stereoisomers

Compound A having molecular formula $C_5{H}_{7}Cl$ is itself not optically active but can be resolved into

enantiomers. The reaction of A with excess $H_2$ in the presence of a Pt catalyst gives achiral compound $B$

having the molecular formula $C_5{H}_{9}Cl.$ The reaction of A with potassium tert$-$butoxide $($a strong base$)$

gives $1,3-$cyclopentadiene. Identify the structures of A and $B$ including all stereoisomers.

The specific stereochemical description of the relationship between the following two

compounds is that they are: