1: 95 percent / DMAP, Et3N / dimethylformamide / 36 h / 46 - 50 °C 3: 72 percent / NaBH4, CeCl3 / methanol / 3 h / -78 °C 4: 1.) O3, 2.) NaBH4 / 1. MeOH, CH2Cl2, -78 gradC; 2. -78 gradC to 25 gradC 5: 97 percent / imidazole / dimethylformamide / 5 h / 25 °C 6: 1.) MsCl, pyridine, 2.) LAH / 1. 25 gradC, 17 h.; 2. DME, 0 gradC to 25 gradC, 17 h. 7: 96 percent / KH / tetrahydrofuran / 1.5 h / 25 °C 8: 1.) HF/H2O, 2.) Jones reagent / 1. CH3CN, THF, 25 gradC, 3 h; 2. CH3COCH3, 0 gradC to 25 gradC, 15 min. 9: 1. I2, 2,4,6-collidine, CH3CN, 25 gradC, 35 min; 2. Bu3SnH, AIBN, PhH, 80 gradC, 6 h. 10: 92 percent / NaBH4 / methanol / -78 - 25 °C 11: 82 percent / H2 / 10percent Pd/C, 70percent HClO4 / methanol / 25 °C / 2068.6 Torr 12: 2.) DIBAL / 1. 90 gradC, 50 h; 2. THF, 0 gradC, 1 h. View Scheme