Homoannular Heteroannular (cisoid) (transoid 1=214nm Parent 1=253nm 217(acyclic) Increments for Double bond extending conJugation

4.1 Addition of hx to Alkenes. p100 Hydrohalogenation General reaction mechanism: electrophilic addition Attack of electrophile(such as hBr)on T bond of alkene Produces carbocation and bromide ion Carbocation is an electrophile, reacting with nucleophilic bromide ion

What is an alkyl halide An organic compound containing at least one carbon-halogen bond (C-X) X(F, Cl, Br, Replaces h Can contain many C-X bonds

Definitions Conjugated double bonds are separated by one single bond. Example: 1, 3-pentadiene. Isolated double bonds are separated by two or more single bonds. 1, 4-pentadiene. Cumulated double bonds are on adjacent carbons. Example: 1, 2-pentadiene

To determine reaction''s mechanism, look at: Equilibrium constant Free energy change Enthalpy Entropy Bond dissociation energy Kinetics >Activation energy

一、什么是蛋白质? 蛋白质(protein)是由许多氨基酸 amino acids)通过肽键(peptide bond)相连形成的高分子含氮化合物