Multi-step reaction with 7 steps
1: 61 percent / LDA / tetrahydrofuran / -78 °C / 1.) 30 min, 2.) 1 h
2: tetrahydrofuran / -78 deg C, 70 min; -50 deg C, 20 min; 0 deg C, 20 min
3: 15percent aq. H2SO4 / tetrahydrofuran / 0.33 h / 0 °C
4: 83 percent / Et3N, DMAP / CH2Cl2 / 4 h / Ambient temperature
5: 83 percent / DBU / toluene / 1 h / Heating
6: 1.) LDA, 2.) AcOH, aq. NaOAc / 1.) THF, benzene, r.t., 30 min; THF, r.t.; 2 h, 2.) THF, r.t., 5 h
7: LDA / tetrahydrofuran / 1.) -78 deg C, 15 min, 2.) r.t., 30 min
With
dmap; sulfuric acid; sodium acetate; acetic acid; 1,8-diazabicyclo[5.4.0]undec-7-ene; triethylamine; lithium diisopropyl amide;
In
tetrahydrofuran; dichloromethane; toluene;
DOI:10.1039/a606719k