Selective Addition:Markovnikov's Rule 。 Markovnikov's rule:Proton added to double bond of an alkene goes to the carbon atom that already holds the greater number of hydrogens. Markovnikov's rule (extended):In an electrophilic addition to the alkene,the electrophile adds in such a way that it generates the most stable intermediate. CHs CHs CH3-C-CH-CH3 add Hto secondary carbon CH,-C-CH-CH, →HBr H Br tertiary carbocation CH3 CH一CCH-CH add H to tertiary carbon CH,-C-CH-CH; H Br secondary carbocation 9 2013 Pearson Education Inc.Selective Addition: Markovnikov’s Rule • Markovnikov’s rule: Proton added to double bond of an alkene goes to the carbon atom that already holds the greater number of hydrogens. • Markovnikov’s rule (extended): In an electrophilic addition to the alkene, the electrophile adds in such a way that it generates the most stable intermediate. 9 © 2013 Pearson Education Inc