dipyridinium dichromate; oxalic acid in dichloromethane 4 h; Ambient temperature; Yields of byproduct given. Title compound not separated from byproducts;

1: 1.) NaH / 1.) THF, 30 min, 2.) THF, 2 h 2: 1.) (COCl)2, DMSO, 2.) Et3N / 1.) CH2Cl2, -78 deg C, 2 h, 2.) 2.) CH2Cl2, from -78 deg C to RT, 75 min 3: 78 percent / LiBH4 / tetrahydrofuran / 0.5 h / 20 °C 4: 86 percent / LiCl, MsCl, s-collidine / dimethylformamide / 2 h / 0 - 20 °C 5: 79 percent / tetrahydrofuran / 12 h / Ambient temperature 6: 91 percent / tetra-n-butylammonium fluoride / tetrahydrofuran / 3 h / 20 °C 7: 73 percent / TPAP, NMO, 4 Angstroem sieves / CH2Cl2 / 3 h 8: 85 percent / tetrahydrofuran; hexane / 2 h / 0 - 20 °C View Scheme

1: 1.) NaH / 1.) THF, 30 min, 2.) THF, 2 h 2: 1.) (COCl)2, DMSO, 2.) Et3N / 1.) CH2Cl2, -78 deg C, 2 h, 2.) 2.) CH2Cl2, from -78 deg C to RT, 75 min 3: 78 percent / LiBH4 / tetrahydrofuran / 0.5 h / 20 °C 4: 86 percent / LiCl, MsCl, s-collidine / dimethylformamide / 2 h / 0 - 20 °C 5: 79 percent / tetrahydrofuran / 12 h / Ambient temperature 6: 91 percent / tetra-n-butylammonium fluoride / tetrahydrofuran / 3 h / 20 °C 7: 73 percent / TPAP, NMO, 4 Angstroem sieves / CH2Cl2 / 3 h View Scheme

in dichloromethane T=-20°C;