Radical addition with HBr 与HB的自由基加成反应 Paco H hBi Br Br H
HBr (PhCO2 )2 Br H H Br + Radical addition with HBr (与HBr的自由基加成反应) p.110
4.4 Addition ofhe to p Alkenes: Hydration OH H H PO H C-C H-C-C-H 250°C H OH VIa C-H
4 . 4 A d diti o n of H 2 O to A l k e nes : H y d r ation p.100
HC HC Reaction of an alkene with acid (HA) lds a carbocation intermediate HC H C-C-H+ A Water acts as a nucleophile, using a lone pair of electrons on oxygen to form a bond to carbon. The oxygen m, having donated electrons, is now trivalent and has the positive H-0:H 3C-C-C-H 3C H Loss of an H" from oxygen then yields the neutral alcohol product and regenerates the acid catalyst HO H HgC-C-C-H+H-A IgC H 2. Methyl-2-propanol C2004 Thomson-Brooks/Cole
Addition of Water to Alkenes: p105 Oxymercuration(羟汞化反应) For laboratory-scale hydration of an alkene Use mercuric acetate in thf followed by sodium borohydride Markovnikov orientation via mercurinium ion THF tetrahydrofuran HgOAc OAc HgOAC .Ch H,O cha nabh CH OH oCH3= OAC
Addition of Water to Alkenes: Oxymercuration(羟汞化反应) • For laboratory-scale hydration of an alkene • Use mercuric acetate in THF followed by sodium borohydride • Markovnikov orientation via mercurinium ion p.105
Addition of water toAlkenes. p. 06 ydroboration((硼氢化反应) Borane (Bh3 is electron deficient is a Lewis acid Borane adds to an alkene to give an organoborane H C Brown H H BH B-H+ C-c H Borane An organoborane
Addition of Water toAlkenes: Hydroboration(硼氢化反应) • Borane (BH3 ) is electron deficient is a Lewis acid • Borane adds to an alkene to give an organoborane p.106 H.C.Brown