1. 1H NMR (270.1 MHz, CDCl3) δ 2.01 (s, OH), 2.97 (m, H-8), 3.83 (s, 4-OMe), 3.84a(H-9a), 3.85 (s, 3, 5-OMe), 3.89 (s, 3′, 4′-OMe), 3.95 (dd,J= 11.5, 6, H-9b), 4.74 (ddd,J= 14, 2.5, 2, H-9′ax), 4.86 (d,J= 6, H-7), 4.93 (dd,J= 14. 2, H-9′eq), 6.39 (dd,J= 4.2, H-7′), 6.63 (s, H-2, 6), 6.70 (d,J= 2, H-2′), 6.72 (dd,J= 8, 2, H-6′), 6.87 (d,J= 8, H-51),13C NMR (67.8 MHz, CDCl3) δ 55.8 (C-8), 55.8 (3′, 4′-OMe), 56.0 (3, 5-OMe), 60.7 (4-OMe), 62.7 (C-9), 70.1 (C-9′), 82.2 (C-7), 103.1 (C-2, 6), 111.2 (C-5′), 111.4 (C-2′), 120.6 (C-61), 121.6 (C-7′), 129.9 (C-8′), 136.9 (C-1), 137.4 (C-4), 139.2 (C-1′), 148.1 (C-4′), 148.8 (C-3′), 153.3 (C-3, 5).aOverlapped with methoxyl protons
2. Hydroboration of the acetate of1by diborane in THF followed by the oxidation with H2O2/ NaOH gave 8′-hydro-7′-hydroxymagnofargesin (2, 60%). This diol was readily cyclized by refluxing in acidic EtOH, in consequence, (+)-epimagnolin A (4.9%) and (+)-magnolin (28.8%) were obtained. (+)-Epimagnolin A had [α]D+110.6° (c0.2, CHCl3),band (+)-magnolin had [α]D+49.4° (c0.5, CHCl3).cbMiyazawa, M., Ishikawa, Y., Kasahara, H., Yamanaka, J., and Kameoka, H. (1994)Phytochemistry35, 611.cMiyazawa, M., Kasahara, H. and Kameoka, H. (1992)Phytochemistry31, 3666
3. HRMSm/z434.1946 ([M]+, calcd for C23H28O7: 434.1940).1H NMR (500.0 MHz, CDCl3) δ 2.52 (m, H-8′), 2.77 (m,J= 15.5, 10.5, 8, H-8), 3.33 (dd,J= 9, 8, H-9a), 3.62 (dd,J= 9, 8, H-9b), 3.67 (dd, 11, 3.5, H-9′a), 3.74 (s, 4-OMe), 3.77 (s, 3, 5-OMe), 3.80 (s, 3′, 4′-OMe), 3.94 (m, H-9′b), 4.46 (d,J= 7, H-7′), 4.69 (d,J= 10, 5, H-7), 6.45 (s, H-2, 6), 6.74 (d,J= 8, H-5′), 6.78 (dd, 2, 8, H-6′), 6.82 (d,J= 2, H-2′).13C NMR (125.65 MHz, CDCl3) δ 48.8 (C-81), 52.0 (C-8), 60.8 (C-9), 70.3 (C-9′), 73.2 (C-7′), 83.2 (C-7), 102.8 (C-2, 6), 109.3 (C-2′), 111.0 (C-5′), 118.8 (C-6′), 135.1 (C-1′), 137.4 (C-1), 137.5 (C-4), 149.2 (C-41), 148.9 (C-3′), 153.2 (C-3, 5)