hydrogen; palladium on activated charcoal in ethanol P=3309.8 Torr; 3 h;

Multi-step reaction with 4 steps 1: 43 percent / BF3 / diethyl ether2: 87 percent / Sn<N(TMS)2>2 / tetrahydrofuran; hexane / 3 h / Ambient temperature3: 79 percent Turnov. / LDA / tetrahydrofuran; heptane / 1 h / -78 °C4: 98 percent / Oxone<*> / tetrahydrofuran; H2O / 0 deg C to room temperature, 15 min