Page 99 - Pharm.Org.Chem-I 02-06-05-101
P. 99
b) Addition of HX to unsymmetric alkenes
√
x
• This addition follows Markovnicoff’s rule
Markovnikov’s rule
• Old concept:
When an unsymmetrically substituted alkene reacts with a hydrogen
halide, the hydrogen (H) adds to the carbon that has the greater
number of hydrogen substituents, and the halogen (X) adds to the
carbon having fewer hydrogen substituents.
• Modern concept:
In the ionic addition of hydrogen halide to an alkene, protonation of
the double bond occurs in the direction that gives the most stable
carbocation.
97
