Chapter 13, Problem 13.11P

Interpretation Introduction

Interpretation:

The choice of the leaving group on C2 of the propyl chain in the given transformation and how the transformation can be carried out is to be determined.

Concept introduction:

In an elimination reaction, the leaving group and a proton are eliminated, usually from adjacent carbons to produce a double bond between the two carbons. If more than one adjacent carbons have protons present on them, the major product of elimination is determined by the conditions under which the reaction is carried out. In general, the most stable, i.e., the most substituted alkene is formed preferentially. This is called the Zaitsev product. The less substituted Hofmann product is formed when the leaving group is bulky and the proton on the less substituted adjacent carbon is in an anti position to the leaving group rather than the proton on the more substituted adjacent carbon.

An E1 reaction involves the formation of a carbocation in the first, rate-determining step. A carbocation may be subject to rearrangement, and therefore, can lead to the formation of a mixture of stereoisomers.