Isopropanol → HCID 59352697, compound

Participants

Reaction Steps

To a stirred solution of triphenylphosphine (0.23 g, 0.89 mmol) in anhydrous tetrahydronfuran (200 mL) at 0° C. under nitrogen were added diethyl azodicarboxylate (0.14 mL, 0.89 mmol), isopropanol (0.23 mL, 2.97 mmol) and 6-hydroxy-1′-[(2R)-tetrahydrofuran-2-ylmethyl]spiro[1-benzofuran-3,3′-indol]-2′(1H)-one (0.20 g, 0.59 mmol). The reaction mixture was stirred at ambient temperature for 16 h, and then the reaction was quenched with ammonium chloride solution. The solvent was removed, and the residue was dissolved in ethyl acetate (100 mL), which was washed with water, brine, dried over sodium sulfate and filtered. The filtrate was concentrated to dryness, and the residue was purified by flash chromatograph with 25% ethyl acetate in hexanes to afford 6-(1-methylethoxy)-1′-[(2R)-tetrahydrofuran-2-ylmethyl]spiro[1-benzofuran-3,3′-indol]-2′(1′H)-one (0.19 g, 85%) as colorless liquid; 1H NMR (300 MHz, CDCl3) δ7.33-7.25 (m, 1H), 7.16-6.99 (m, 3H), 6.58 (d, J=8.4 Hz, 1H), 6.50 (d, J=1.8 Hz, 1H), 6.33 (dd, J=8.4, 2.1 Hz, 1H), 4.93 (d, J=9.0 Hz, 1H), 4.68 (d, J=9.0 Hz, 1H), 4.53-4.43 (m, 1H), 4.33-4.23 (m, 1H), 4.00-3.66 (m, 4H), 2.10-1.66 (m, 4H), 1.31 (d, J=6.0 Hz, 6H); MS (ES+) m/z 380.0 (M+1), 402.0 (M+23).

Provenance & Evidence