Chapter 12, Problem 12.7P

Interpretation Introduction

Interpretation:

The structure of the initial alkene, which could have been used in the reaction with molecular chlorine in carbon tetrachloride yielding a racemic mixture of

$\left(\text{R, R}\right)\text{- 3, 4 - dichloro - 2 - methylhexane}$ and its enantiomer, is to be drawn.

Concept introduction:

Alkene reacts with molecular halide in carbon tetrachloride ${\text{(CCl}}_{\text{4}}\text{)}$ to yield a mixture of dihaloalkanes. Molecular halide undergoes anti addition across a carbon-carbon double bond. To account for the stereochemistry of the reaction, the mechanism must proceed through a cyclic halonium ion intermediate. If the mixture of products is diastereomers, then the mixture would be optically active. If the products are either enantiomers or a meso compound, then the mixture is optically inactive. A symmetrically substituted alkene may yield a meso compound, which would be optically inactive.