Question

draw the major product as a planar projection (not chair conformation) for the E2 reaction below. Do not include stereochemical configurations for the chirality centers.

Answer 1

Concepts and reason

In ${{\rm{E}}_{\rm{2}}}$ elimination reaction, two adjacent substituents eliminated from an alkyl halide to form alkene. The mechanism of this reaction is concerted (i.e. elimination occur in one step).

Fundamentals

In ${{\rm{E}}_{\rm{2}}}$ elimination reaction, the eliminating groups must be anti to each other (i.e. $180{\;^{\rm{o}}}$ to each other). For example, in chair conformation of cyclohexane both eliminating groups (i.e. H and Cl) must be in axial positions.

The reaction is,

Ans:

Thus, the major ${{\rm{E}}_{\rm{2}}}$ organic products is,