Chapter 4, Problem 88P

(a)

Interpretation Introduction

Interpretation:

The possible stereoisomers of the given compound has to be drawn.

Concept introduction:

Stereoisomers are isomers which have different spatial arrangement in spite of same bond connectivity.  Stereoisomers are due to the presence of stereocenter.

Asymmetric center is a stereocenter which arises to hydrocarbons if the carbon is bonded to four different groups.

Fischer projections: the asymmetric center (carbon) represents as the point of intersection of two perpendicular lines, in which the horizontal lines represent the bonds that project out of the plane of the paper and the vertical lines represent the bonds that away from the plane of the paper.

(b)

Interpretation Introduction

Interpretation:

The optically inactive stereoisomers from the above four stereoisomers of the given compound has to be determined.

Concept introduction:

Optical activity of a molecule is the interaction between molecule and plane-polarized light.

Molecule having asymmetric center shows optical activity except mesocompounds.

Asymmetric center is a stereocenter which arises to hydrocarbons if the carbon is bonded to four different groups.

Mesocompounds has asymmetric centers and a plane of symmetry, so the molecule superimposable on its mirror image, thereby the compound is achiral.

If the four groups attached to both asymmetric centers of a compound are identical, then the compound is a mesocompound.