Question

Compound W, C8H17Br, and X, C8H17Cl, are products of the radical bromination (W), and chlorination (X), of 2,4-dimethylhexane. W and X are each chiral. W reacts readily in water to form a chiral substitution product Y, C8H17OH. Reaction of a single enantiomer of W produces a single enantiomer of Y as the only substitution product. X likewise reacts readily in water though at a slower rate than W; a chiral substitution product Z, C8H17OH, is again formed. Unlike W, however, reaction of a single enantiomer of X produces Z that is nearly racemic. Propose structures for W and X.

Answer 1

Answer:

The possible structures are shown in figure.

Explanation:

The seven isomers that could be formed from the given compound due to radical halogenation are shown in the figure.

We have mentioned only chlorine as group for showing just the chiral nature of the compound.

A chiral compound has a carbon with all the four groups different from each other.

There are three structures which are chiral (as shown).

W is the brominated product

X is the chlorinated product.

1) W reacts readily in water to form a chiral substitution product Y, C8H17OH.

Reaction of a single enantiomer of W produces a single enantiomer of Y as the only substitution product.: It means that the substitution is SN2 which is possible if the compund is not tertiary.

2) X likewise reacts readily in water though at a slower rate than W; a chiral substitution product Z, C8H17OH, is again formed. Unlike W, however, reaction of a single enantiomer of X produces Z that is nearly racemic.

It means that it will undergo SN1 reaction,. So the alkyl halide must be tertiary.

The possible structures are shown in figure.