Реакция #358729

Уравнение реакции

dihydroartemisinin

trifluoroacetic anhydride

→

9,10-anhydro-10-deoxoartemisinin

Выход 36.3%

Растворители

dichloromethane

Условия реакции

Обработка

1. 1
   КонцентрированиеThe solution was then concentrated in vacuo
2. 2
   ДругоеThe residue was purified by flash chromatography (SiO2; ether:hexane from 0.5:9.5 to 1.5:8.5)

Методика

To a solution of dihydroartemisinin (500 mg, 1.86 mmol) in dichloromethane (28 ml) at 0° C. under nitrogen was added 4-(N,N-dimethylamino)pyridine (37 mg) and trifluoroacetic anhydride (0.79 ml, 5.58 mmol). The mixture was allowed to warm to room temperature and stirred overnight. The solution was then concentrated in vacuo. The residue was purified by flash chromatography (SiO2; ether:hexane from 0.5:9.5 to 1.5:8.5) to give 9,10-anhydro-10-deoxoartemisinin (9,10-anhydroartemisinin) (180 mg, 25%) as a white solid. M.p. 100° C.; [α]D20.5+155.74° (c.0.0101 in CHCl3); νmax (film): 2948, 2922, 2862, 2850, 1684, 1432, 1372, 1334, 1198, 1178, 1158, 1142, 1114, 1078, 1028, 1016, 992, 954, 944, 904, 880, 828, 812; δH: 6.18 (1H, s, H-10), 5.54 (1H, s, H-12), 2.40 (1H, ddd, J=17.1, 13.2, 4.14 Hz, H-9), 2.00-2.09 (2H, m), 1.88-1.95 (1H, m), 1.07-1.73 (8H, m), 1.58 (3H, d, J=1.37 Hz, H-16), 1.42 (3H, s, H-14), 0.98 (3H, d, J=5.98 Hz, H-15); m/z (EI): 380 (M+); Anal. Calc. for C15H22O4: C, 67.67; H, 8.27; Found: C, 67.63; H, 8.51

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