CHEM 2E03 Chapter Notes - Chapter 9: Three Steps, Chiral Ligand, Meso Compound
Document Summary
Addition and elimination represent an equilibrium that is temperature dependent. In order for g to be negative, enthalpy must be larger than entropy: at low temperatures, entropy is small, enthalpy term dominates g = neg. Addition reactions thermodynamically favoured at low temps: at high temps, entropy term will be large and dominate over enthalpy. G wll be positive, reactants will be favoured. Reverse process, elimination, will be thermodynamically favoured at high temps. Hydrohalogenation: treatment of alkenes with hx (where x = cl, br, or i), in which h and x are added across the pi bond. Markovnikov addition: h is placed at the vinylic position already bearing the larger number of h atoms, the halogen is placed at the more substituted position (bearing more alkyl groups) Anti-markovnikov addition: addition in the presence of peroxides (roor) cause anti-markovnikov addition. Regiochemical outcome of hx addition can be controlled by choosing whether or not to use peroxides.
