oxalyl dichloride; dimethyl sulfoxide in dichloromethane T=-60°C; 0.5 h;

1: 100 percent / thionyl chloride / 74 h / Ambient temperature 2: 1.) chlorotrimethylsilane, Et3N, 2.) Et3N, Pb(NO3)2 / 1) CH2Cl2, reflux, 1 h; 2) CH2Cl2, MeOH, rt, 96 h 3: 100 percent / DMSO, oxalyl chloride / CH2Cl2 / 0.5 h / -60 °C View Scheme

1: 1.) chlorotrimethylsilane, Et3N, 2.) Et3N, Pb(NO3)2 / 1) CH2Cl2, reflux, 1 h; 2) CH2Cl2, MeOH, rt, 96 h 2: 100 percent / DMSO, oxalyl chloride / CH2Cl2 / 0.5 h / -60 °C View Scheme

1: 1.) chlorotrimethylsilane, Et3N, 2.) Et3N, Pb(NO3)2 / 1) CH2Cl2, reflux, 1 h; 2) CH2Cl2, MeOH, rt, 96 h 2: 100 percent / DMSO, oxalyl chloride / CH2Cl2 / 0.5 h / -60 °C View Scheme

1: 82 percent / TMSCl, Pb(NO3)2 / CH2Cl2 2: (COCl)2, Et3N / dimethylsulfoxide / -60 °C View Scheme

sodium tetrahydroborate in methanol; dichloromethane T=-78°C; 16 h; Inert atmosphere;

1: 1.) NaHMDS, 2.) MoOPH / 1) THF, -78 deg C, 2 h; 2) THF, -78 - -15 deg C, 2.5 h 2: 92 percent / NaBH4 / methanol; tetrahydrofuran / 4 h / -78 °C 3: 97 percent / PPTS / dimethylformamide; acetone / 24 h / 5 °C 4: 1.) n-BuLi, 2.) LiClO4 / 1) hexane, THF, -78 - -65 deg C, 5 min; 2) THF, hexane, -78 deg C, 2 h 5: 100 percent / LiEt3BH / tetrahydrofuran / 3 h / 0 °C 6: 100 percent / conc. HCl, H2 / Pd/C / methanol / 13 h / 2689.2 Torr View Scheme