1: With Schwartz's reagent in tetrahydrofuran T=20°C; 0.666667 h; 2: With N-bromosuccinmide in tetrahydrofuran T=20°C; 0.166667 h;

1: 1.) butyllithium / 1.) THF, hexane, -78 degC, 2.) 25 degC, 1h 2: 1.) diisobutylaluminium hydride, 2.) bromine / 1.) THF, hexane, 0 degC, 15 min, 25 degC, 4h, 2.) CH2Cl2, THF, hexane, -78 degC, 15 min View Scheme

(i) nBuLi, hexane, THF, (ii) /BRN= 471223/; Multistep reaction;

bromine; sodium methylate 1.) dichloromethane, - 78 deg C, 30 min; 0 deg C, 30 min, 2.) methanol, 0 deg C, 30 min; 25 deg C, 2 h; Yield given. Multistep reaction;

1: (E)-1-bromo-1-trimethylsilyl-2-phenylethene With tert.-butyl lithium in diethyl ether; pentane T=-78°C; 2: 2-benzyl-3-phenylpropionaldehyde in diethyl ether; pentane T=-78 - 0°C; 3: in diethyl ether; N,N-dimethyl-formamide; pentane T=50°C; Peterson allenation; Further stages.;

sodium methylate in methanol T=40°C; 4 h; Yield given;