Chapter 13, Problem 13.17P

Interpretation Introduction

Interpretation:

The given transformation shows another way in which H and $\text{Cl}$ atoms can be added to $\text{(E)-3-methylpent-2-ene}$ to undo an E2 reaction. H and $\text{Cl}$ atoms are in an anticoplaner conformation about the indicated $\text{C-C}$ bond. The three substituents that are missing in the given compound are to be supplied.

Concept introduction:

The precursor of an E2 reaction is constructed from an alkene by adding the hydrogen and leaving group (L) substituents to the alkene carbon atoms in an anti fashion. Groups attached to the same side of the $\text{C=C}$ bond in the target should appear on the same side of the $\text{H -C - C - L}$ plane in the precursor.