caesium carbonate; palladium (II) bromide; 2-(dicyclohexylphosphino)-2',4',6'-tri-i-propyl-1,1’-biphenyl in 1,4-dioxane T=20°C; 12 h;

1: TBHP, Ti(O-i-Pr)4, diisopropyl L-tartrate, 4 Angstroem molecular sieves / CH2Cl2; 2,2,4-trimethyl-pentane / 44 h / -20 °C 2: tetraethylammonium fluoride hydrate / acetonitrile / 6 h / 60 °C View Scheme

1: TBHP, Ti(O-i-Pr)4, diisopropyl L-tartrate, 4 Angstroem molecular sieves / CH2Cl2; 2,2,4-trimethyl-pentane / 44 h / -20 °C 2: tetraethylammonium fluoride hydrate / acetonitrile / 6 h / 60 °C View Scheme