sodium hydrogencarbonate; sodium sulfite in water T=70 - 80°C; 50 h;

(i) nBuLi, Et2O, (ii) aq. HCl, (iii) aq. NaOH, MeOH; Multistep reaction;

1: H2O / 168 h / 60 °C 2: 94 percent / NOCl / pyridine / 2 h / -15 - -10 °C 3: 78 percent / Al2O3 / diethyl ether; CH2Cl2 / 2 h / 0 °C 4: 82 percent / triethylamine / acetonitrile / 27 h / Ambient temperature 5: 32 percent / acetonitrile / 48 h / Heating View Scheme

potassium carbonate in tetrahydrofuran 1 h; Heating;