CHM136H1 Lecture Notes - Lecture 29: Elimination Reaction, Alkane Stereochemistry, Cyclohexene

• School: UTSG
• Department: Chemistry
• Course: CHM136H1

Document Summary

E2 and e1 reactions: summary of reactions. Transition state is the most important part of the reaction. Determines how much of one side is made. Cyclohexane rings need to possess anti-periplanar geometry in order to undergo e2 reactions. Hydrogen and leaving group in cyclohexanes need to be transdixaial. Cis can still go through other reactions such as e1. Trans-diaxial requirement is met in isomeric methyl and neomethyl by removal of hcl. E1: comprises two steps and involves a carbocation. Start out along same lines as sn1 reactions. Dissociation leads to loss of proton from neighbouring carbon rather than sub. E1 and sn1 are direct competitors (but e2 and sn2 are not) They exhibit first order kinetics consistent with rate-lim, unimolecular dissoc process. Do not exhibit any deuterium kinetic isotope effect. Do not have specific geometric requirements like e2 reactions. Below is a direct comparison of the elimination methods. Also note how e1 doesn"t have 100% predictability.