Compound 9
(2S,2'R,3a'S,4'S,8'S,10'S,13a'S)-13a'-(((2S,4R,5S,6S)-5-Acetyl-4,5-dihydroxy-6-methyltetrahydro-2H-pyran-2-yl)oxy)-2'-(dimethoxymethyl)-8',10',12'-trihydroxy-7'-methoxy-5'-methyl-3a',4',8',9',10',13a'-hexahydro-2'H,11'H-spiro[oxirane-2,1'-[2,4]epoxyfuro[3,2-b]naphtho[2,3-h]chromen]-11'-one
From: Component-based syntheses of trioxacarcin A, DC-45-A1 and structural analogues
View in PubChem | MDL Molfile | ChemDraw
InChIKey YSQOWKZSYDEFGJ-HXUDUTLZSA-N
Synthetic procedure: See article for the definitive version of this procedure and for full experimental details.
Triethylamine–trihydrofluoride (18 μL, 110 μmol, 30 equiv) was added to a solution of benzylic alcohol 8 (3.0 mg, 3.7 μmol, 1 equiv) in acetonitrile (0.5 mL) at 23 °C. The reaction flask was covered with aluminum foil to exclude light. After 21 h, the product solution was partitioned between dichloromethane (50 mL) and saturated aqueous sodium chloride solution (20 mL). The layers were separated. The aqueous layer was extracted with dichloromethane (3 × 10 mL). The organic layers were combined and the combined solution was dried over sodium sulfate. The dried solution was filtered and the filtrate was concentrated. The residue was purified by preparatory HPLC (Agilent Prep-C18 column, 10 μm, 30 × 150 mm, UV detection at 270 nm, gradient elution with 20→50% acetonitrile in water, flow rate: 15 mL/min) to provide after concentration the pure trioxacarcinose B monoglycoside 9 (1.7 mg, 66%). TLC: (ethyl acetate) Rf = 0.18 (UV, CAM); 1H NMR (500 MHz, CDCl3) δ: 13.84 (br, 1H), 7.48 (s, 1H), 5.85 (d, 1H, J = 2.6 Hz), 5.46 (t, 1H, J = 2.9 Hz), 5.37 (d, 1H, J = 4.0 Hz), 5.24 (d, 1H, J = 4.0 Hz), 5.02 (q, 1H, J = 6.6 Hz), 4.93 (dd, 1H, J = 12.8, 5.5 Hz), 4.77 (s, 1H), 4.25 (d, 1H, J = 9.5 Hz), 4.16 (br, 1H), 3.92 (s, 3H), 3.71 (brd, 1H, J = 8.8 Hz), 3.63 (s, 3H), 3.49 (s, 3H), 3.00 (br, 1H), 2.98 (d, 1H, J = 5.9 Hz), 2.89 (d, 1H, J = 5.9 Hz), 2.74 (ddd, 1H, J = 13.2, 5.5, 2.9 Hz), 2.62 (s, 3H), 2.49 (s, 3H), 2.44 (dt, 1H, J = 14.7, 3.7 Hz), (dt, 1H, J = 13.2, 3.3 Hz), 2.11 (ddd, 1H, J = 14.7, 2.6, 1.5 Hz), 1.09 (d, 3H, J = 6.6 Hz); 13C NMR (125 MHz, CDCl3) δ: 210.4, 203.3, 162.4, 151.8, 144.4, 142.6, 135.7, 129.6, 116.6, 114.6, 107.3, 104.7, 101.5, 99.7, 94.9, 79.6, 71.4, 70.2, 69.2, 68.3, 67.7, 63.8, 62.9, 61.9, 56.9, 56.1, 48.2, 45.7, 37.0, 31.6, 27.8, 20.4, 14.5; FTIR (neat), cm–1: 3431 (br w), 2926 (m), 1713 (m), 1622 (s), 1256 (s), 1103 (s); HRMS (ESI): Calcd for (C33H38O16 + Na)+: 713.2052. Found: 713.2029.
