Natural Product Research
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d6, 100 MHz) d 154.2 (C-2), 149.2 (C-3), 148.2 (C-9), 145.8(C-10), 135.2 (C-14), 126.6 (C-4a),
124.3 (C-12), 122.1 (C-12a), 119.5 (C-14a), 118.8 (C-13), 115.9 (C-1), 113.9 (C-11), 108.9
(C-8a), 103.7 (C-4), 102.3 (OCH2O), 61.5 (C-6), 60.7 (C-8), 60.4 (9-OMe), 56.5 (10-OMe), 45.6
(NMe), 23.9 (C-5); ESI-HRMS [M]þ calcd for C21H22NO4 352.1543, found 352.1483.
1
Compound (5): obtained as yellow amorphous powder, isolated yield: 20.9%, H NMR
(DMSO-d6, 400 MHz) d 9.96 (s, 1H, H-8), 8.97 (s, 1H, H-13), 8.04 (d, 1H, J ¼ 8.8 Hz, H-11),
7.82 (d, 1H, J ¼ 8.8 Hz, H-12), 7.79 (s, 1H, H-1), 7.08 (s, 1H, H-4), 6.53, 6.17 (two s, each 2H, 2
£ OCH2O), 4.88 (t, 2H, J ¼ 6.0 Hz, H-6), 3.19 (t, 2H, J ¼ 6.0 Hz, H-5); 13C NMR (DMSO-d6,
100 MHz) d 150.3 (C-2), 148.2 (C-3), 147.6 (C-8), 145.0 (C-9), 144.3 (C-10), 137.3 (C-14),
132.8 (C-4a), 131.0 (C-12a), 122.2 (C-12), 121.5 (C-13), 121.4 (C-11), 121.0 (C-14a), 112.1
(C-8a), 108.9 (C-1), 105.8 (C-4), 105.0, 102.6 (2 £ OCH2O), 55.7 (C-6), 26.8 (C-5); ESI-HRMS
[M]þ C19H14NO4 320.0917, found 320.0888.
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Compound (6): obtained as yellow amorphous powder, isolated yield: 20.7%, H NMR
(DMSO-d6, 400 MHz) d 9.90 (s, 1H, H-8), 8.95 (s, 1H, H-13), 8.21 (d, 1H, J ¼ 9.2 Hz, H-11), 8.00
(d, 1H, J ¼ 9.2 Hz, H-12), 7.80 (s, 1H, H-1), 7.09 (s, 1H, H-4), 6.17 (s, 1H, OCH2O), 4.93 (t, 2H,
J ¼ 6.0 Hz, H-6), 4.09 (s, 3H, 9-OMe), 4.07 (s, 3H, 10-OMe), 3.20 (t, 2H, J ¼ 6.0 Hz, H-5); 13
C
NMR (DMSO-d6, 100 MHz) d 150.9 (C-2), 150.3 (C-3), 148.2 (C-9), 145.9 (C-10), 144.2(C-8),
138.0 (C-14), 133.5 (C-4a), 131.2 (C-12), 127.3 (C-12a), 124.0 (C-14a), 121.9 (C-13), 120.9
(C-1), 120.7 (C-11), 108.9 (C-8a), 105.9 (C-4), 102.6 (OCH2O), 62.4 (C-6), 57.6 (9-OMe), 55.7
(10-OMe), 26.9 (C-5); ESI-HRMS [M]þ calcd for C20H18NO4 336.1230, found 336.1185.
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Compound (7) obtained as white amorphous powder, isolated yield: 68.0%, H NMR
(DMSO-d6, 400 MHz) d 6.92 (s, 1H, H-1), 6.75 (d, 1H, J ¼ 8.0 Hz, H-11), 6.70 (s, 1H, H-4),
6.63 (d, 1H, J ¼ 8.0 Hz, H-12), 6.00–5.94 (m, 4H, 2 £ OCH2O), 3.95 (d, 1H, J ¼ 16 Hz, H-8),
3.46–3.32(m, 2H, overlapped, H-80, H-14), 3.07 (1H, dd, J ¼ 12.0, 4.0 Hz, H-6), 2.94–2.85 (m,
1H, H-13), 2.62–2.43 (m, 3H, H-130, 80, 60); 13C NMR (DMSO-d6, 100 MHz) d 146.2 (C-2),
145.9 (C-3), 145.0 (C-9), 143.2 (C-10), 131.2 (C-4a), 129.1 (C-12a), 128.0 (C-14a), 121.4
(C-12), 117.1 (C-8a), 108.6 (C-1), 107.0 (C-11), 106.2 (C-4), 101.3, 101.0 (2 £ OCH2O), 59.6
(C-14), 52.7 (C-8), 51.0 (C-6), 36.2 (C-13), 29.4 (C-5); ESI-HRMS [M þ H]þ C19H18NO4
324.1236, found 324.1182.
1
Compound (8): obtained as white amorphous powder, isolated yield: 58.4%, H NMR
(DMSO-d6, 400 MHz) d 6.91 (s, 1H, H-1), 6.88 (d, 1H, J ¼ 8.4 Hz, H-11), 6.84 (d, 1H,
J ¼ 8.4 Hz, H-12), 6.66 (s, 1H, H-4), 5.94 (brs, 2H, OCH2O), 4.05 (d, 1H, J ¼ 16 Hz, H-8) 3.77,
3.72 (two s, 6H, 2 £ OCH3), 3.38–3.28 (m, 2H, overlapped, H-80, H-14), 3.08 (1H, dd, J ¼ 11.2,
4.0 Hz, H-6), 2.94–2.86 (m, 1H, H-13), 2.61–2.41 (m, 3H, H-130, 80, 60); 13C NMR (DMSO-d6,
100 MHz) d 150.3 (C-2), 146.2 (C-3), 145.9 (C-9), 144.9 (C-10), 131.4 (C-4), 128.7 (C-4a),
128.1 (C-12a), 128.0 (C-14a), 124.2 (C-12), 111.7 (C-1), 108.5 (C-8a), 106.2 (C-11), 101.0
(OCH2O), 60.0 (9-OMe), 59.5 (C-14), 56.2 (10-OMe), 54.0 (C-8), 51.2 (C-6), 36.2 (C-13), 29.5
(C-5); ESI-HRMS [M þ H]þ C20H22NO4 340.1549, found 340.1539.
1
Compound (9): obtained as white amorphous powder, isolated yield: 65.8%, H NMR
(DMSO-d6, 400 MHz) d 7.00 (s, 1H, H-1), 6.84, 6.75 (two d, 1H each, J ¼ 8.0 Hz, H-11, H-12),
6.70 (s, d, H-4), 6.00–5.95 (m, 4H, 2 £ OCH2O), 5.11–5.00 (m, 1H, H-14), 4.88–4.63 (m, 1H,
H-8), 4.01 (d, 1H, J ¼ 14.0 Hz, H-13), 3.48 (d, 1H, J ¼ 14.0 Hz, H-130), 3,40–3.35 (m, 1H,
overlapped, H-80), 2.96 (t, 1H, J ¼ 12.0 Hz, H-5), 2.66 (d, 1H, J ¼ 12.0 Hz, H-6), 2.55–2.43(m,
2H, H-50, H-60), 1.99 (s, 3H, NCH3); 13C NMR (DMSO-d6, 100 MHz) d 150.7 (C-2), 146.6
(C-3), 145.6 (C-9), 145.2 (C-10), 141.9 (C-12a), 132.1 (C-14a), 130.9 (C-4a), 130.3 (C-8a),
126.1 (C-12), 110.5 (C-1), 110.0 (C-11), 104.8 (C-4), 101.0, 100.8(2 £ OCH2O), 69.5 (C-14),
60.7 (C-6), 51.9 (C-8), 47.7 (C-13), 42.0 (N-CH3), 32.0 (C-5); ESI-HRMS [M þ H]þ calcd for
C20H22NO5 356.1498, found 356.1490.
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Compound (10): obtained as white amorphous powder, isolated yield: 85.8%, H NMR
(DMSO-d6, 400 MHz) d 7.01 (s, 1H, H-1), 6.85, 6.80 (two d, 1H each, J ¼ 8.4 Hz, H-11, H-12),