1. 1: Colorless cubic crystals, m.p. 192–193°C, [α]D20+4.7 (c 0.5, CHCl3); IR (KBr): 3390, 1451, 1372, 1126cm−1; 1H NMR (400MHz, CDCl3) and 13C NMR (100MHz, CDCl3): see Table 1; HR-ESIMS m/z: C24H35NNaO7 [M+Na]+ 472.2311 (calcd. 472.2306).
2. 2: Colorless cubic crystals, m.p. 161–163°C, [α]D20−23.6 (c 0.5, CHCl3); IR (KBr): 3449, 1650, 1457, 1086cm−1; 1H NMR (400MHz, CDCl3) and 13C NMR (100MHz, CDCl3): see Table 1. HR-ESIMS: m/z C24H38NO7 [M+H]+ 452.2629 (calcd. 452.2643).
3. 3: Colorless needle crystals, [α]D20−0.97 (c 0.65, CHCl3); IR (KBr): 3499, 1459, 1378, 1085cm−1; 1H NMR (400MHz, CDCl3) and 13C NMR (100MHz, CDCl3): see Table 1. HR-ESIMS: m/z: C24H35NNaO7 [M+Na]+ 456.2362 (calcd. 456.2357).