tert-butyl 4-oxo-1-oxa-9-azaspiro[5.5]undecane-9-carboxylate

反应条件: temp:0.00; pressure:0.00; stir:

反应条件: temp:0.00; pressure:0.00; stir:

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: The title compound was prepared following the method reported here for Compound 26a, substituting ethyl 2-oxo-4-oxa-8-azaspiro[4.5]decane-8-carboxylate with Compound 29b. After the usual work-up procedure the oily residue was purified by means of automated flash chromatography (SP1®TM-Biotage; Petroleum Ether-EtOAc gradient 9:1 to 6:4) to give 0.96 g of the title compound as a grey solid. Yield: 57.3% The title compound was prepared After the usual work-up procedure the oily residue was purified by means of automated flash chromatography (SP1®TM-Biotage; Petroleum Ether-EtOAc gradient 9:1 to 6:4)

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To a solution of Compound 29a (1.6 g, 5.99 mmol) in a mixture of dioxane-water (32.9 mL and 11 mL respectively) under stirring at r.t. was added a 4% sol. of osmium tetroxide in water (0.762 μL, 0.125 mmol). After 2 h, was added portionwise milled sodium metaperiodate (2.56 g, 12 mmol) affording a suspension that tended to become clear gray from brownish. After 4 h H2O was added, extracting with EtOAc, washing with H2O, drying over Na2SO4, evaporating the solvent to dryness. The residual tawny semi-solid was purified by means of automated flash chromatography (SP1®TM-Biotage; Petroleum Ether-EtOAc 7:3) to give 0.96 g of the title compound as a grey solid. Yield: 59.5% affording a suspension extracting with EtOAc washing with H2O drying over Na2SO4 evaporating the solvent to dryness The residual tawny semi-solid was purified by means of automated flash chromatography (SP1®TM-Biotage; Petroleum Ether-EtOAc 7:3)