Question

3. The principal side reaction of an Sn1 reactions is E1 elimination. Discuss the possibility of this side reaction. What are some ways to confirm that the final mixture contains only 2-chloro-2-methylbutane and none of the elimination product (which has a lower boiling point than 2-chloro-2-methylbutane)

Answer 1

E1 happens along with SN1. The relative amounts of of SN1 and E1 depend on conditions. At higher temperature elimination i.e E1 is preseerd. Poor nucleophiles ( like conjugate bases of strong acids like H2SO4, H3PO4) if used , elimination is preferred. Thus temperature and strength of nucleophile dtermines SN1 or E1 .

When we have eliminated product along with Substituted product the boiling points of both are different. Hence when boiling we can oberve some part boilling off while some part remaining at boiling point of alkene which is lower ( alkene is elimination product)