1.1: 98 percent / (i-Pr)2NEt / dimethylformamide / 12 h / 23 °C 2.1: 75 percent / NEt3 / 12 h / 23 °C 3.1: PPTS / 8 h 4.1: Bu4NF; AcOH / tetrahydrofuran / 5 h / 23 °C 5.1: LDA; HMPA / tetrahydrofuran / 2 h / -78 - -50 °C 5.2: tetrahydrofuran / 6 h / -78 - 0 °C 6.1: LiOH; H2O / 12 h / 25 °C 7.1: PhSO2Cl; pyridine / 8 h / 0 °C 8.1: 90 percent / PPTS / ethanol / 3 h / Heating 9.1: 95 percent / DCC; DMAP 10.1: H2 / 10 percent Pd/C / 12 h 11.1: 87 percent / tetrahydrofuran / 1 h / 23 °C View Scheme

1.1: 98 percent / (i-Pr)2NEt / dimethylformamide / 12 h / 23 °C 2.1: 75 percent / NEt3 / 12 h / 23 °C 3.1: PPTS / 8 h 4.1: Bu4NF; AcOH / tetrahydrofuran / 5 h / 23 °C 5.1: LDA; HMPA / tetrahydrofuran / 2 h / -78 - -50 °C 5.2: tetrahydrofuran / 6 h / -78 - 0 °C 6.1: LiOH; H2O / 12 h / 25 °C 7.1: PhSO2Cl; pyridine / 8 h / 0 °C 8.1: 90 percent / PPTS / ethanol / 3 h / Heating 9.1: 95 percent / DCC; DMAP View Scheme