BENZYL CYCLOPENT-3-EN-1-YLCARBAMATE

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

实验步骤: A solution of 3-cyclopentene-1-carboxylic acid (Depres and Greene, J. Org. Chem. 1962, 27:2395-2398) (30.5 g, 0.272 mole) in dry benzene (360 mL) was stirred while a solution of diphenylphosphoryl azide (Aldrich, 74.85 g, 0.272 mole as 97%) and triethylamine (41.7 mL, 0.299 mole) in benzene (130 mL) was added over 20 minutes. The solution was refluxed for 2 hours and then benzyl alcohol (32.4 mL, 0.313 mole) was added. The solution was refluxed for 20 hours, cooled, and concentrated in vacuo to a brown oil. A solution of the oil in ethyl acetate (600 mL) was washed with 0.5 N hydrochloric acid (300 mL), then water (2×350 mL), then saturated aqueous sodium bicarbonate (300 mL), and dried (sodium sulfate). Evaporation left title compound as white solid (41.0 g, 69%), 1H-NMR consistent with structure. Recrystallization of such a sample from ethyl acetate-hexanes gave benzyl N-(3-cyclopenten-1-yl)carbamate as colorless waxy crystals, m.p. 56-57° C. was added over 20 minutes The solution was refluxed for 2 hours The solution was refluxed for 20 hours cooled concentrated in vacuo to a brown oil A solution of the oil in ethyl acetate (600 mL) was washed with 0.5 N hydrochloric acid (300 mL) water (2×350 mL), then saturated aqueous sodium bicarbonate (300 mL), and dried (sodium sulfate) Evaporation left title compound as white solid (41.0 g, 69%) Recrystallization of such a sample from ethyl acetate-hexanes

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

实验步骤: To a solution of benzyl cyclopent-3-en-1-ylcarbamate (920 mg, 4.23 mmol) in DCM (20 mL), was added m-CPBA (2.0 g, 7.6 mmol) in portions at 0° C. The mixture was warmed up to RT and stirred at RT for 2 hours. The reaction was quenched by addition of sat. aqueous solution of K2CO3, and the resulting mixture was extracted with DCM (20 mL×3). The combined organic layers were dried over Na2SO4, and then concentrated in vacuo to afford the crude benzyl 6-oxabicyclo[3.1.0]hex-3-ylcarbamate (1.5 g), which was used in the next step directly. The reaction was quenched by addition of sat. aqueous solution of K2CO3 the resulting mixture was extracted with DCM (20 mL×3) The combined organic layers were dried over Na2SO4 concentrated in vacuo

反应条件: temp:90.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To a cooled solution of cyclopent-3-ene-1-carboxylic acid (2.0 g, 17.8 mmol) and DPPA (6.05 g, 22.0 mmol) in toluene (50 mL) was added TEA (2.0 g, 22.0 mmol) dropwise at 0° C. The resulting mixture was then warmed and heated at 90° C. for 1 hour. After being added phenylmethanol (4.0 g, 40 mmol), the mixture was heated at 90° C. for additional 4 hours and then concentrated in vacuo. The residue was purified by silica-gel chromatography to afford benzyl cyclopent-3-en-1-ylcarbamate as a white solid (1.9 g). The resulting mixture was then warmed the mixture was heated at 90° C. for additional 4 hours concentrated in vacuo The residue was purified by silica-gel chromatography

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

实验步骤: A solution of 3-cyclopentene-1-carboxylic acid (Depres and Greene, J. Org. Chem. 1962, 27:2395-2398) (30.5 g, 0.272 mole) in dry benzene (360 mL) was stirred while a solution of diphenylphosphoryl azide (Aldrich, 74.85 g, 0.272 mole as 97%) and triethylamine (41.7 mL, 0.299 mole) in benzene (130 mL) was added over 20 minutes. The solution was refluxed for 2 hours and then benzyl alcohol (32.4 mL, 0.313 mole) was added. The solution was refluxed for 20 hours, cooled, and concentrated in vacuo to a brown oil. A solution of the oil in ethyl acetate (600 mL) was washed with 0.5 N hydrochloric acid (300 mL), then water (2×350 mL), then saturated aqueous sodium bicarbonate (300 mL), and dried (sodium sulfate). Evaporation left title compound as white solid (41.0 g, 69%), 1H-NMR consistent with structure. Recrystallization of such a sample from ethyl acetate-hexanes gave benzyl N-(3-cyclopenten-1-yl)carbamate as colorless waxy crystals, m.p. 56-57° C. was added over 20 minutes The solution was refluxed for 2 hours The solution was refluxed for 20 hours cooled concentrated in vacuo to a brown oil A solution of the oil in ethyl acetate (600 mL) was washed with 0.5 N hydrochloric acid (300 mL) water (2×350 mL), then saturated aqueous sodium bicarbonate (300 mL), and dried (sodium sulfate) Evaporation left title compound as white solid (41.0 g, 69%) Recrystallization of such a sample from ethyl acetate-hexanes