Anti-Markovnikov ? C CH3-C-CH-CH3 CH3 Br CH3-C=CH-CH3 +Br. X CH3 CH3-C-CH-CH3 Br Tertiary radical is more stable,so that intermediate forms faster. 二> Chapter8 11
Chapter 8 11 Anti-Markovnikov ?? • Tertiary radical is more stable, so that intermediate forms faster. => CH3 C CH3 CH CH3 + Br CH3 C CH3 CH CH3 Br CH3 C CH3 CH CH3 Br X
Hydration of Alkenes H OH alke ne alcohol Reverse of dehydration of alcohol Use very dilute solutions of H2SO,or H3PO4 to drive equilibrium toward hydration. => Chapter8 12
Chapter 8 12 Hydration of Alkenes • Reverse of dehydration of alcohol • Use very dilute solutions of H2SO4 or H3PO4 to drive equilibrium toward hydration. => C C + H2O H + C H C OH alkene alcohol
Mechanism for Hydration c=c +H二OH H20 - c-c 3O: Chapter 8 13
Chapter 8 13 Mechanism for Hydration C + H C + H2O C H C O H H + C + H2O H C O H H + C H C O H + H3O + => C C H O H H + + C + H2O H C +
Orientation for Hydration Markovnikov product is formed. H CH马 CH-C=CH-CH+H二OH CHy-C-CH-CH:+ H CH3 H20: +0.H H H CH3-C-CH-CH3 月-0 H20: Chapter8 14
Chapter 8 14 Orientation for Hydration • Markovnikov product is formed. + CH3 C CH3 CH CH3 H O H H + + + H2O H CH CH3 CH3 CH3 C H2O CH3 C CH3 CH CH3 O H H H + H2O CH3 C CH3 CH CH3 O H H =>
Indirect Hydration Oxymercuration-Demercuration >Markovnikov product formed >Anti addition of H-OH >No rearrangements ·Hydroboration >Anti-Markovnikov product formed >Syn addition of H-OH => Chapter8 15
Chapter 8 15 Indirect Hydration • Oxymercuration-Demercuration ➢Markovnikov product formed ➢Anti addition of H-OH ➢No rearrangements • Hydroboration ➢Anti-Markovnikov product formed ➢Syn addition of H-OH =>