Furan, 2-ethynyl- → pomecin A

Beteiligte Stoffe

Reaktionsschritte

A mechanically stirred solution of bromoacetylene 5 (35 g, 121 mmol) and ethynylfuran 8 (23% w/w, 16.7 g, 182 mmol) in 400 mL of pyrrolidine under nitrogen was cooled via ice-water bath. Copper (I) iodide (3.69 g, 19 mmol) was added in one portion and after 5 min the cooling bath was removed and the homogeneous mixture was stirred an additional 1 h. The dark red reaction was quenched by addition of 850 mL of water with stirring. The orange-yellow suspension was extracted with 4×300 ml of diethyl ether. The combined organic layers were washed with 3×100 mL of water and 100 mL of brine, dried over sodium sulfate, and concentrated in vacuo to a dark red oil. The residue was resuspended in 100 mL of 10% ethyl acetate in hexanes and passed through a pad of silica gel in a flitted funnel. The pad was washed with an additional 4×50 mL of solvent and concentrated in vacuo to give 21.0 g of crude 9 as a dark red oil.

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