Synthesis
A new structure based on (2S,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-2-yl((4R,4aS,6aR,9S,11aR,11bS)-9-(((2S,3R,4S,5S,6R)-4,5-dihydroxy-6-(hydroxymethyl)-3-(((2S,3R,4S,5S,6R )-3,4,5-trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-2-yl)oxy)tetrahydro-2H-pyran-2-yl)oxy-4,11b-dimethyl-8-methylenetetradecahydro-6a,9-methylcyclohepta[a]naphthalene-4-carboxylic acid ester was synthesized by 10% sulfuric acid hydrolysis reaction. The reaction conditions were conventional hydrolysis conditions without additional catalyst or special temperature control. The product was purified in 93% yield with the melting point of 228.4-230.8 °C. The structure of the product was confirmed by IR, 1H NMR, 13C NMR and HRMS.The IR spectrum showed that the characteristic absorption peaks were located at 3448, 2955, 2924, 2848, 1736, 1692, 1453, 1404, 1373, 1320, 1268, 1214, 1180, 1150, 1108, 973, 950, 796, 589 cm-1 . 796, 589 cm-1.1H NMR (400 MHz, CDCl3) δ: 2.64 (dd, J = 18.64, 3.76 Hz, 1H), 2.17 (d, J = 13.40 Hz, 1H), 1.90-1.37 (m, 13H), 1.25 (s, 3H), 1.22-1.14 (m, 3H), 1.06- 1.03 (m, 1H), 0.98 (s, 3H), 0.95-0.88 (m, 1H), 0.78 (s, 3H).13C NMR (100 MHz, CDCl3) δ: 224.22, 184.33, 56.79, 57.62, 56.09, 54.83, 49.73, 49.59, 44.38. 42.02, 40.42, 38.99, 38.34, 32.80, 29.69, 22.32, 20.57, 19.55, 14.04. HRMS (ESI) m/z: [M + Na]+ Calculated value C20H30O3Na 341.2093, measured value 341.2085.
References
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