Reaktion #358729

Reaktionsgleichung

dihydroartemisinin

trifluoroacetic anhydride

→

9,10-anhydro-10-deoxoartemisinin

Ausbeute 36.3%

Lösungsmittel

dichloromethane

Reaktionsbedingungen

Aufarbeitung

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

Vorschrift

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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