反应详情

To a solution of 6.42 g (40.1 mmol) of benzyl propiolate from step A above in 25 ml of anhydrous THF was added 0.93 g (0.80 mmol) of tetrakis(triphenylphosphine)palladium(0) followed by a solution of 12.6 g (42.1 mmol) of tributyltin hydride in 25 mL of anhydrous THF over 15 min. After stirring at room temperature overnight the solvent was removed under reduced pressure. The residue was filtered through a pad of Celite® which was then washed with hexanes. The filtrate was concentrated in vacuo and the crude product was purified by silica gel chromatography eluting with a 0-15% ethyl acetate in hexane gradient to afford the title compound as a colorless oil (13 g, 73%). 1H NMR (CDCl3, 500 MHz) δ 7.39 (m, 5H), 6.99 (d, J=2.7 Hz, 1H), 5.98 (d, J=2.7 Hz, 1H), 5.20 (s, 2H), 1.47 (m, 6H), 1.30 (m, 6H), 0.96 (m, 6H), 0.89 (t, J=7.4 Hz, 9H).

1. customwas removed under reduced pressure
2. filtrationThe residue was filtered through a pad of Celite® which
3. washwas then washed with hexanes
4. concentrationThe filtrate was concentrated in vacuo
5. customthe crude product was purified by silica gel chromatography
6. washeluting with a 0-15% ethyl acetate in hexane gradient