1: 95 percent / TBAF 2: (COCl)2, DMSO, Et3N 3: 75 percent / CrCl2 4: 74 percent / Pd(PPh3)2Cl2, Et2NH, CuI 5: 80 percent / TsNHNH2, NaOAc 6: 80 percent / PPTS / ethanol / 16 h / 75 °C View Scheme

<b>Multi-step reaction with 10 steps<br /> </b>1: 76 percent / TBAF / tetrahydrofuran / 12 h / 50 &deg;C<br />2: 1.) NaH / 1.) THF, room temperature, 30 min, 2.) 40 min<br />3: 85 percent / (COCl)2, DMSO, Et₃N / CH₂Cl₂ / -78 - 20 &deg;C<br />4: 81 percent / InCl₃ / ethyl acetate<br />5: 94 percent / i-Pr₂NEt<br />6: 90 percent / H₂ / Rh/Al₂O₃ <br />7: 94 percent / TBAF<br />8: 84 percent / Et₃N, DMAP<br />9: 94 percent / pyridine<br />10: 83 percent / LiEt₃BH<br /> <br /> &nbsp;

<b>Multi-step reaction with 12 steps<br /> </b>2: 75 percent / pyridine / 1.) 0 deg C, 30 min, 2.) room temperature, 18 h<br />3: 76 percent / TBAF / tetrahydrofuran / 12 h / 50 &deg;C<br />4: 1.) NaH / 1.) THF, room temperature, 30 min, 2.) 40 min<br />5: 85 percent / (COCl)2, DMSO, Et₃N / CH₂Cl₂ / -78 - 20 &deg;C<br />6: 81 percent / InCl₃ / ethyl acetate<br />7: 94 percent / i-Pr₂NEt<br />8: 90 percent / H₂ / Rh/Al₂O₃ <br />9: 94 percent / TBAF<br />10: 84 percent / Et₃N, DMAP<br />11: 94 percent / pyridine<br />12: 83 percent / LiEt₃BH<br /> <br /> &nbsp;