1: Grubb's 2nd generation catalyst / dichloromethane / 6 h / 40 °C 2: hydrogenchloride; water / tetrahydrofuran / 20 h View Scheme

1.1: pyridinium chlorochromate / dichloromethane / 20 °C 2.1: potassium tert-butylate / diethyl ether / 2 h / 20 °C 2.2: 0 - 20 °C 3.1: trichlorophosphate / 8.5 h / 0 - 20 °C 4.1: boron tribromide / dichloromethane / 1.08 h / 0 °C / Inert atmosphere 5.1: sodium dihydrogenphosphate; sodium chlorite; 2-methyl-but-2-ene / water; tert-butyl alcohol 6.1: di-isopropyl azodicarboxylate; triphenylphosphine / toluene / 1.5 h 7.1: water; 2,3-dicyano-5,6-dichloro-p-benzoquinone / dichloromethane / 1 h / 20 °C 8.1: Grubb's 2nd generation catalyst / dichloromethane / 6 h / 40 °C 9.1: hydrogenchloride; water / tetrahydrofuran / 20 h View Scheme

1: boron tribromide / dichloromethane / 1.08 h / 0 °C / Inert atmosphere 2: sodium dihydrogenphosphate; sodium chlorite; 2-methyl-but-2-ene / water; tert-butyl alcohol 3: di-isopropyl azodicarboxylate; triphenylphosphine / toluene / 1.5 h 4: water; 2,3-dicyano-5,6-dichloro-p-benzoquinone / dichloromethane / 1 h / 20 °C 5: Grubb's 2nd generation catalyst / dichloromethane / 6 h / 40 °C 6: hydrogenchloride; water / tetrahydrofuran / 20 h View Scheme

1.1: potassium tert-butylate / diethyl ether / 2 h / 20 °C 1.2: 0 - 20 °C 2.1: trichlorophosphate / 8.5 h / 0 - 20 °C 3.1: boron tribromide / dichloromethane / 1.08 h / 0 °C / Inert atmosphere 4.1: sodium dihydrogenphosphate; sodium chlorite; 2-methyl-but-2-ene / water; tert-butyl alcohol 5.1: di-isopropyl azodicarboxylate; triphenylphosphine / toluene / 1.5 h 6.1: water; 2,3-dicyano-5,6-dichloro-p-benzoquinone / dichloromethane / 1 h / 20 °C 7.1: Grubb's 2nd generation catalyst / dichloromethane / 6 h / 40 °C 8.1: hydrogenchloride; water / tetrahydrofuran / 20 h View Scheme

1.1: potassium carbonate / acetone / 4 h / Reflux 2.1: lithium aluminium tetrahydride / diethyl ether / 1 h / 0 °C 3.1: pyridinium chlorochromate / dichloromethane / 20 °C 4.1: potassium tert-butylate / diethyl ether / 2 h / 20 °C 4.2: 0 - 20 °C 5.1: trichlorophosphate / 8.5 h / 0 - 20 °C 6.1: boron tribromide / dichloromethane / 1.08 h / 0 °C / Inert atmosphere 7.1: sodium dihydrogenphosphate; sodium chlorite; 2-methyl-but-2-ene / water; tert-butyl alcohol 8.1: di-isopropyl azodicarboxylate; triphenylphosphine / toluene / 1.5 h 9.1: water; 2,3-dicyano-5,6-dichloro-p-benzoquinone / dichloromethane / 1 h / 20 °C 10.1: Grubb's 2nd generation catalyst / dichloromethane / 6 h / 40 °C 11.1: hydrogenchloride; water / tetrahydrofuran / 20 h View Scheme

1.1: lithium aluminium tetrahydride / diethyl ether / 1 h / 0 °C 2.1: pyridinium chlorochromate / dichloromethane / 20 °C 3.1: potassium tert-butylate / diethyl ether / 2 h / 20 °C 3.2: 0 - 20 °C 4.1: trichlorophosphate / 8.5 h / 0 - 20 °C 5.1: boron tribromide / dichloromethane / 1.08 h / 0 °C / Inert atmosphere 6.1: sodium dihydrogenphosphate; sodium chlorite; 2-methyl-but-2-ene / water; tert-butyl alcohol 7.1: di-isopropyl azodicarboxylate; triphenylphosphine / toluene / 1.5 h 8.1: water; 2,3-dicyano-5,6-dichloro-p-benzoquinone / dichloromethane / 1 h / 20 °C 9.1: Grubb's 2nd generation catalyst / dichloromethane / 6 h / 40 °C 10.1: hydrogenchloride; water / tetrahydrofuran / 20 h View Scheme

1: trichlorophosphate / 8.5 h / 0 - 20 °C 2: boron tribromide / dichloromethane / 1.08 h / 0 °C / Inert atmosphere 3: sodium dihydrogenphosphate; sodium chlorite; 2-methyl-but-2-ene / water; tert-butyl alcohol 4: di-isopropyl azodicarboxylate; triphenylphosphine / toluene / 1.5 h 5: water; 2,3-dicyano-5,6-dichloro-p-benzoquinone / dichloromethane / 1 h / 20 °C 6: Grubb's 2nd generation catalyst / dichloromethane / 6 h / 40 °C 7: hydrogenchloride; water / tetrahydrofuran / 20 h View Scheme