Trifluoroacetic anhydride → Anhydrodihydroartemisnin

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

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

ORD-Eintrag

ord-ecd3c3e79a51495e9b6b5df1f0e7e318

Quelldatensatz

uspto-grants-2008_11

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07452915B2