Methanol → HCID 69541951, compound

Participants

Reaction Steps

To a solution of 18 (1.38 g, 5.63 mmol) in dry pyridine (30 mL) was added dropwise under argon atmosphere t-butyldimethylsilyl chloride (1.10 g, 7.32 mmol) and the mixture was stirred for 10 h at room temperature. Then the mixture was poured onto a saturated aqueous sodium hydrogen carbonate solution (100 mL) and extracted with chloroform (3×150 mL). Combined extracts were washed with water (2×200 mL) and then dried over sodium sulphate and evaporated under reduced pressure. The residue was purified by silica gel column chromatography [eluent: stepwise gradient of methanol (2-10%) in methylene chloride] to give pure 19 (1.74 g, 86% yield) as a white solid: mp 202-204° C.; UV (ethanol): λmax 241 nm (ε 7800), 284 nm (ε 7800), λmin 226 nm (ε 6600), 263 nm (ε 5400); 1H NMR (DMSO-d6): δ 7.77 (d, 1H, H-6, J6-F5=7.1 Hz), 7.7-7.3 (br d, 2H, NH2), 6.88 (dd, 1H, H-1′, J1′-2′=4.9 Hz and J1′-F5=1.9 Hz), 5.24 (d, 1H, OH-3′, JOH-3′=4.6 Hz), 4.4 (m, 1H, H-2′), 4.0 (m, 1H, H-4′), 3.8-3.7 (m, 2H, H-5′ and H-5″), 2.2 (m, 1H, H-3′), 1.7 (m, 1H, H-3″), 0.84 (s, 9H, (CH3)3C—Si), 0.06 (s, 6H, (CH3)2Si); MS (matrix GT): FAB>0 m/z 1437 (4M+H)+, 1078 (3M+H)+, 719 (2M+H)+, 360 (M+H)+, 231 (S)+, 130 (BH2)+, 115 (TBDMS)+; FAB<0 m/z 1076 (3M−H)−, 717 (2M−H)−, 358 (M−H)−, 128 (B)−; [α]D20=−107 (c, 0.88 DMSO).

Provenance & Evidence