Multi-step reaction with 6 steps
1: 52 percent / tetrahydrofuran / 12 h / -78 - 20 °C
2: imidazole / dimethylformamide / 12 h / Ambient temperature
3: 88 percent / MeLi*LiBr / diethyl ether / 7 h / Ambient temperature
4: 1.) n-BuLi, Cp2ZrCl2, 2.) NIS / 1) hexane, THF, -80 --> -55 deg C, 1 h, rt, 7 h; 2) hexane, THF, CH2Cl2, -50 deg C, 1 h, rt, 1 h
5: 97 percent / DBU / CH2Cl2 / 120 h / Ambient temperature
6: 1.) t-BuLi, 2.) ZnBr2, 3.) Pd(PPh3)4 / 1) pentane, Et2O, -78 deg C, 15 min; 2) pentane, Et2O, -10 deg C, 1 h; 3) pentane, Et2O, THF, rt, 2 h
With
1H-imidazole; N-iodo-succinimide; tetrakis(triphenylphosphine) palladium(0); n-butyllithium; zirconocene dichloride; methyllithium lithium bromide; tert.-butyl lithium; 1,8-diazabicyclo[5.4.0]undec-7-ene; zinc dibromide;
In
tetrahydrofuran; diethyl ether; dichloromethane; N,N-dimethyl-formamide;
DOI:10.1021/jo970605m