反应详情

A stirred solution of 3,4-bis-allyloxy-xanthen-9-one (236.4 mg, 0.767 mmol) and diphenyl ether (3.0 mL) was refluxed in an oil bath at 190° C. for 11 h. The solution was cooled to room temperature and product was purified twice by flash column chromatography (dichloromethane) to yield 28.0 mg (12%) of the title compound as a white solid. 1H NMR (CDCl3, 300 MHz): δ 7.95 (dd, J1=7.69 Hz, J2=1.65, 1H), 7.56 (ddd, J1=8.17 Hz, J2=7.07, J3=1.58, 1H), 7.34 (d, J=7.14Hz, 1H), 7.08 (m, 1H), 5.22 (m, 1H), 4.69 (m, 1H), 4.53 (m, 1H), 3.91 (d, J=7.97 Hz, 1H), 3.53 (ddd, J1=6.11 Hz, J2=3.43, J3=2.06, 1H), 2.82 (dd, J1=13.33 Hz, J2=5.35, 1H), 2.63 (m, 1H), 2.51 (dd, J1=13.60 Hz, J2=9.48, 1H), 1.90 (m, 1H), 1.78 (ddd, J1=12.22 Hz, J2=10.38, J3=2.39, 1H).

1. customproduct was purified twice by flash column chromatography (dichloromethane)