Triphenylphosphine → ethyl (2'-oxo-6,7-dihydro-5H-spiro[indeno[5,6-b]furan-3,3'-indol]-1'(2'H)-yl)acetate

Participants

Reaction Steps

To a solution of ethyl [3-(6-hydroxy-2,3-dihydro-1H-inden-5-yl)-3-(hydroxymethyl)-2-oxo-2,3-dihydro-1H-indol-1-yl]acetate (4.20 mmol) in anhydrous THF (60.0 mL) was added triphenylphosphine (1.43 g, 5.46 mmol) and diethyl azodicarboxylate (0.95 g, 5.46 mmol) at 0° C. The reaction mixture was stirred at ambient temperature for 16 h and quenched with saturated ammonium chloride (20.0 mL). The mixture was extracted with ethyl acetate (3×50.0 mL). The combined organic layers was dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo to dryness. The residue was subjected to column chromatography (ethyl acetate/hexane, 1/4) to give the title compound (0.25 g, 16% in three steps): 1H NMR (300 MHz, CDCl3) δ 7.29 (td, 1H), 7.22-7.17 (m, 1H), 7.07 (t, 1H), 6.81 (s, 1H), 6.78 (d, 1H), 6.65 (s, 1H), 4.95 (d, 1H), 4.71 (d, 1H), 4.64 (d, 1H), 4.42 (d, 1H), 4.24 (q, 2H), 2.84 (t, 2H), 2.73-2.65 (m, 2H), 2.10-1.95 (m, 2H), 1.29 (t, 3H); MS (ES+) m/z 364 (M+1).

Provenance & Evidence