1.1: 100 percent / PDC / dimethylformamide / 20 °C 2.1: DIPEA / CH2Cl2 / 0.5 h / 20 °C 3.1: 240 mg / DMAP / CH2Cl2 / 3 h / 20 °C 4.1: 75 percent / NaOMe / methanol / 2 h / Heating 5.1: 74 percent / H2 / 10 percent Pd/C / methanol / 0.07 h 6.1: oxalyl chloride; DMSO; DIPEA / CH2Cl2 / -78 - 20 °C 7.1: aq. HCl / CH2Cl2 / 0.5 h 8.1: LDA / tetrahydrofuran; hexane / 15 h / -78 °C 8.2: 77 percent / tetrahydrofuran; hexane / -78 - 20 °C View Scheme

Multi-step reaction with 5 steps 1: 100 percent / PDC / dimethylformamide / 20 °C2: DIPEA / CH2Cl2 / 0.5 h / 20 °C3: 240 mg / DMAP / CH2Cl2 / 3 h / 20 °C4: 75 percent / NaOMe / methanol / 2 h / Heating5: 74 percent / H2 / 10 percent Pd/C / methanol / 0.07 h