1: 1) LDA / 1) -78 deg C 2: 94 percent / Et3N / (Ph3P)2PdCl2 / 75 °C 3: H2, Lindlar catalyst, quinoline / hexane 4: 2,2,4-trimethyl-pentane / Heating 5: 82 percent / ion-exchange resin AG 50W-X4 / methanol / 48 h / Ambient temperature; in the dark View Scheme

1: 1.) n-BuLi / 1.) hexane, THF, -70 deg C, 30 min, 2.) THF, -70 deg C, 90 min 2: 76 percent / AG-50WX4(resin) / methanol / 16 h / Ambient temperature View Scheme

Multi-step reaction with 6 steps 1: 95 percent / pyridine, ozone / methanol; CH2Cl2 / 0.42 h / -78 °C2: 1) 2,6-di-tert-butylpyridine, 2a) TMSTf, 2b) Et3N, MeOH / 1) CH2Cl2, -78 deg C, 5 min, 2a) -78 deg C, 2 h, 2b) -78 deg C, 5 min then to RT3: TiCl4 / CH2Cl2 / 12 h / -78 °C4: 92 percent / DMAP, i-Pr2NEt / CH2Cl2 / 18 h / 0 °C5: 91 percent / LDA / tetrahydrofuran / 0.5 h / -78 °C