sodium hexamethyldisilazane

1.1: n-butyllithium / hexane; tert-butyl methyl ether / 2 h / -78 °C / Inert atmosphere 1.2: 0.75 h / -78 °C / Inert atmosphere 2.1: diisobutylaluminium hydride / toluene / 3 h / -78 °C 2.2: -50 °C 3.1: 4-(N,N-dimethlyamino)pyridine; diisopropyl-carbodiimide / tetrahydrofuran / 24 h / 20 - 40 °C / Inert atmosphere 4.1: RuCl2(tricyclohexylphosphine)2(benzylidene) / dichloromethane / 18 h / 20 - 40 °C / Inert atmosphere 5.1: tetrabutyl ammonium fluoride; ammonium hydrogen difluoride / tetrahydrofuran / 24 h / 20 - 40 °C 6.1: trimethylaluminum / tetrahydrofuran / 18 h / 20 - 40 °C View Scheme

1.1: Schwartz's reagent / tetrahydrofuran / 3 h / 20 °C / Darkness 1.2: -78 - -20 °C 1.3: 0.5 h / -78 °C 2.1: diisobutylaluminium hydride / toluene / 3 h / -78 °C 2.2: -50 °C 3.1: 4-(N,N-dimethlyamino)pyridine; diisopropyl-carbodiimide / tetrahydrofuran / 24 h / 20 - 40 °C / Inert atmosphere 4.1: RuCl2(tricyclohexylphosphine)2(benzylidene) / dichloromethane / 18 h / 20 - 40 °C / Inert atmosphere 5.1: tetrabutyl ammonium fluoride; ammonium hydrogen difluoride / tetrahydrofuran / 24 h / 20 - 40 °C 6.1: trimethylaluminum / tetrahydrofuran / 18 h / 20 - 40 °C View Scheme

1: (3aR,4R,5R,6aS)-5-(tert-butyldimethylsilyloxy)-4-((S,E)-3-(tert-butyldimethylsilyloxy)-5-phenylpent-1-enyl)hexahydro-2H-cyclopenta[b]furan-2-ol; triphenylphosphonium salt of ω-bromopentanoic acid in tetrahydrofuran T=-10°C; Inert atmosphere; 2: With water; ammonium chloride in tetrahydrofuran; n-heptane; ethyl acetate T=15 - 30°C; Cooling; 3: ethylamine Product distribution / selectivity;

1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride in tetrahydrofuran; N,N-dimethyl-formamide Product distribution / selectivity;

1.1: potassium tert-butylate / tetrahydrofuran / -15 - -10 °C 2.1: triethylamine; DMEG / tetrahydrofuran / 0.17 h / 30 °C 2.2: 2 h / 30 - 70 °C View Scheme

1.1: diisobutylaluminium hydride / hexane; tetrahydrofuran / -85 - -65 °C 2.1: potassium carbonate / methanol / 35 - 45 °C 3.1: potassium tert-butylate / tetrahydrofuran / -15 - -10 °C 4.1: triethylamine; DMEG / tetrahydrofuran / 0.17 h / 30 °C 4.2: 2 h / 30 - 70 °C View Scheme

1.1: potassium carbonate / methanol / 35 - 45 °C 2.1: potassium tert-butylate / tetrahydrofuran / -15 - -10 °C 3.1: triethylamine; DMEG / tetrahydrofuran / 0.17 h / 30 °C 3.2: 2 h / 30 - 70 °C View Scheme

1: potassium carbonate / tetrahydrofuran / 20 - 60 °C 2: tetrahydrofuran View Scheme

1.1: diisobutylaluminium hydride / toluene / -40 °C / Inert atmosphere 1.2: 20 °C 2.1: tetrahydrofuran / -10 °C / Inert atmosphere 2.2: 15 - 30 °C / Cooling View Scheme