Anti-Markovnikov?? C CH CH3-C-CH-CH3 Br CH3-C=CH-CH3 Br CH CH3-C-CH-CH3 Br Tertiary radical is more stable, so that intermediate forms faster > Chapter 8
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 C H OH H C=C h,o alkene alcohol Reverse of dehydration of alcohol Use very dilute solutions of H2 soa or H3PO4 to drive equilibrium toward hydration > hapter 8 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 H 十 C=C +H-0-H H|C|H 十 H H O-H +H2O÷—C-C H H O-H 十 C-C t h,oa HoR hapter 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 mcu Markovnikov product is formed H CH3 3 CH3-C=CH-CH3+H-0-H CH3-C—CH-CH3+H2O H CH PO: CH3-C-CH-CH3∠ o h CH3∠ CH3-C--CH-CH3 H,O: O H > H hapter 8
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 > Chapter 8 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 =>