4710
B. J. Miller et al. / Tetrahedron Letters 53 (2012) 4708–4710
Wollenweber, E.; Jay, M. In The Flavonoids: Advances in Research Since 1980;
Hba), 4.16 (1 H, d, J = 2.53, Hbb), 2.52 (2H, d, J = 7.24, H100a and H100b), 2.01 (1H,
m, H200), 0.93 (6 H, d, J = 6.66, H300a-c and H400a-c); Compound 17: 1H NMR
(600 MHz, CDCl3) d 7.47–7.45 (2H, m, H200 and H600), 7.39–7.36 (2H, m, H300 and
H500), 7.31 (1H, tt, J = 7.31, 2.04 Hz, H400), 7.27–7.23 (1H, m, H5), 6.77 (1H, br d,
J = 16.0 Hz, H30), 6.64–6.58 (3H, m, H2, H4 and H6), 6.46 (1H, dt, J = 11.68,
5.85 Hz, H20), 4.71 (2H, dd, J = 5.85, 1.22 Hz, H10a and H10b), 3.83 (s, 3H, -OMe);
13C NMR (151 MHz, CDCl3) d 133.10 (C-30), 130.04 (C-5), 128.68, 127.98, 126.67,
124.50 (C-20), 107.00 (C-4), 106.58 (C-2), 101.41 (C-6), 68.71 (C-10), 55.32 (-
OMe); MS m/z 240.15 (M+, 5%), 118.10 (10), 117.10 (100), 116.15 (7), 115.10
(30), 91.10 (14); HRMS (AP+) m/z Calcd for C16H17O2 [M+1]+ 241.1229. Found
241.1228. Compound 18: 1H NMR (600 MHz, CDCl3) d 7.32 (2H, t, J = 15.15,
7.57 Hz, H200 and H600), 7.23 (3H, dd, J = 14.64, 7.35 Hz, H300–H500), 6.95 (1H, d,
J = 8.48 Hz, H3), 6.47 (1H, dd, J = 8.48, 2.51 Hz, H4), 6.41 (1H, d, J = 2.51 Hz, H6),
6.32 (1H, ddd, J = 16.97, 10.17, 6.55 Hz, H2’), 5.28 (1H, d, J = 10.17 Hz, H30b), 5.03
(1H, br s, OH), 5.02 (1H, d, J = 16.97 Hz, H30a), 4.87 (1H, d, J = 6.50 Hz, H10), 3.76
Harborne, J. B., Ed.; Chapman and Hall: New York, 1988; Vol. 1, p 235.
4. Wagner, H.; Farkas, L. In The Flavonoids; Harborne, J. B., Mabry, T. J., Mabry, H.,
Eds.; Chapman and Hall: London, 1975; pp 127–213.
5. Van Otterlo, W. A. L.; Ngidi, E. L.; Kuzvidza, S.; Morgans, G. L.; Moleele, S. S.; De
Koning, C. B. Tetrahedron 2005, 61, 9996–10006.
6. Barrett, A. G. M.; Melcher, L. M.; Bezuidenhoudt, B. C. B. Carbohydr. Res. 1992,
232, 259–272.
7. Pine, S. H.; Kim, G.; Lee, V. Org. Synth. Coll. 1993, 8, 512.
8. (a) Lutz, R. P. Chem. Rev. 1984, 84, 206–247; (b) Castro, A. M. M. Chem. Rev. 2004,
104, 2939–3002; (c) Majumdar, K.; Alam, S.; Chattopadhyay, B. Tetrahedron
2008, 64, 597–643; (d) Sonnenberg, F. J. Org. Chem. 1970, 35, 3166–3167; (e)
Cairns, N.; Harwood, L. M.; Astles, D. P.; Orr, A. J. Chem. Soc., Perkin Trans. 1 1994,
3095–3100; (f) Ito, F.; Kumamoto, T.; Ishikawa, T. Tetrahedron Lett. 2005, 46,
7765–7767.
9. Physical characterization: Compound 1: 1H NMR (600 MHz, CDCl3) d 7.70–7.67
(2H, m, H20 and H60), 7.40–7.37 (2H, m, H30 and H50), 7.33 (1H, ddd, J = 7.31,
3.80, 1.14 Hz, H40), 7.18 (1H, ddd, J = 8.22, 8.12, 1.59 Hz, H7), 7.10–7.07 (1H, m,
H5), 7.04–6.99 (2H, m, H6 and H8), 5.51 (1H, t, J = 3.90 Hz, H3), 3.60 (2H, d,
J = 3.85 Hz, H4); 13C NMR (151 MHz, CDCl3) d 128.98 (C-5), 128.72 (C-40), 128.31
(C-7), 127.51, 124.50, 123.29 (C-6), 116.61 (C-8), 96.43 (C-4), 62.67 (C3); MS m/z
208.10 (M+, 65%), 207.10 (100), 178.05 (22), 131.10 (29), 89.05 (17), 77.00 (13);
Compound 2: 1H NMR (600 MHz, CDCl3) d 7.78–7.75 (2H, m, H20 and H60), 7.42–
7.37 (3H, m, H30-H50), 7.29 (1H, dd, J = 7.53, 1.58 Hz, H3), 7.23 (1H, ddd, J = 7.64,
7.86, 1.58 Hz, H5), 7.14 (1H, ddd, J = 7.53, 7.64, 1.16 Hz, H4), 7.07 (1H, dd,
J = 7.86, 1.16 Hz, H6), 6.01 (1H, ddt, J = 20.34, 10.16, 6.74 Hz, H8), 5.12–5.07 (2H,
m, H9a and H9b), 4.93 (1H, d, J = 2.60 Hz, Hba), 4.18 (1H, d, J = 2.60 Hz, Hbb),
3.45 (1H, dd, J = 19.75, 6.68 Hz, H7a), 3.42 (1H, dd, J = 19.75, 6.68 Hz, H7b); 13C
NMR (151 MHz, CDCl3) d 136.75 (C-8), 135.43, 132.32, 130.57, 128.96, 127.68,
125.54, 124.65, 121.17, 116.11 (C-9), 89.24 (C-b), 34.25 (C-7); MS m/z 134.15 (-
C8H7, 100%), 133.10 (36), 119.10 (36), 117.10 (11), 115.10 (31), 107.10 (19),
105.10 (24), 91.10 (50), 79.05 (18), 78.05 (16), 77.05 (33), 51 (18); HRMS (AP+)
m/z Calcd for C17H17O [M+1]+ 237.1279. Found 237.1277. Compound 3: 1H NMR
(600 MHz, CDCl3) d 8.32 (2H, dd, J = 7.90, 1.27 Hz, H2 and H6), 7.71–7.67 (1H, m,
H4), 7.59–7.56 (2H, dd, J = 7.90, J = 1.96, H3 and H5), 7.40–7.35 (2H, m, H30 and
H50), 7.33–7.26 (2H, m, H40 and H60) 6.03 (1H, ddt, J = 16.96, 10.20, 6.65 Hz,
H200), 5.15–5.10 (2H, m, H300a and H300b), 3.48 (1H, dd, J = 19.90, 6.60 Hz, H100a),
(3H, s, -OMe); C NMR (151 MHz, CDCl3) d 141.92, 139.84 (C-20), 130.39 (C-3),
13
128.78, 128.72, 126.87, 121.36, 116.96 (C-30), 106.39 (C-4), 102.59 (C-6), 55.43
(-OMe), 48.95 (C-10); MS m/z 241.15 (17%), 240.15 (M+, 100), 239.15 (54), 225.10
(13), 223.10 (15), 213.10 (15), 211.10 (16), 209.10 (13), 165.15 (10), 163.10 (19),
152.10 (14), 149.10 (14), 137.10 (14), 136.10 (12), 117.10 (11), 116.10 (13),
115.05 (37); HRMS (ES-) m/z Calcd for
C
16H15O2 [M-1]ꢀ 239.1072. Found
239.1074. Compound 19: 1H NMR (600 MHz, CDCl3) d 7.30–7.27 (2H, m, H200 and
H600), 7.21–7.18 (3H, m, H300, H400 and H500), 7.07 (1H, d, J = 8.54 Hz, H6), 6.62 (1H,
dd, J = 8.53, 2.54 Hz, H5), 6.55 (1H, d, J = 2.51 Hz, H3), 6.52 (1H, dd, J = 13.77,
6.08 Hz, H1000), 6.28 (1H, ddd, J = 17.11, 10.20, 6.63 Hz, H20), 5.21 (1H, br d,
J = 10.20 Hz, H30b), 5.06 (1H, br.d, J = 6.63 Hz, H10), 4.94 (1H, br d, J = 17.11 Hz,
H30a), 4.66 (1H, dd, J = 13.75, 1.56 Hz, H2000a), 4.36 (1H, dd, J = 6.08, 1.56 Hz,
H2000b), 3.79 (s, 3H, -OMe); 13C NMR (151 MHz, CDCl3) d 140.18 (C-20), 130.11 (C-
6), 128.58, 128.17 (C-200 and C-600), 126.08, 116.13 (C-30), 108.52 (C-5 and C-1000),
103.80 (C-3), 94.58 (C-2000), 55.40 (-OMe), 47.19 (C-10); MS m/z 266.10 (M+, 95%),
238.10 (52), 224.05 (100), 211.10 (15), 209.05 (34), 189.05 (29), 178.05 (42),
165.10 (34), 161.10 (79), 152.05 (38), 148.05 (26), 142.10 (20), 137.05 (33),
128.10 (18), 115.00 (84), 91.05 (89); Compound 20: 1H NMR (600 MHz, CDCl3) d
7.28 (2H, m, H20 and H60), 7.22–7.16 (3H, m, H30–H50), 6.77 (1H, d, J = 8.53 Hz,
H5), 6.59 (1H, dd, J = 6.23, 1.56 Hz, H2), 6.48 (1H, dd, J = 8.53, 2.60 Hz, H6), 6.45
(1H, d, J = 2.54 Hz, H8), 4.98 (1H, dd, J = 6.23, 3.49 Hz, H3), 4.58 (1H, br d, J = 3.49,
H4), 3.73 (s, 3H, -OMe); 13C NMR (151 MHz, CDCl3) d 139.23 (C-6), 130.65 (C-5),
128.55, 128.12, 126.51, 110.33 (C-2), 105.44 (C-3), 101.08 (C-8), 53.28 (-OMe),
39.18 (C-4); MS m/z 238.15 (M+, 38%), 237.10 (23), 162.15 (11), 161.15 (100),
3.45 (1H, dd, J = 19.90, 6.60 Hz, H100b); 13C NMR (151 MHz, CDCl3) d 164.93 (C-
a)
135.82 (C-200), 133.59 (C-4), 132.13, 130.42 (C-30), 130.14 (C-2 and C-6), 129.52,
128.62 (C-3 and C-5), 127.49 (C-50), 126.22 (C-60), 122.51 (C-40), 116.32 (C-300),
34.70 (C-100); MS m/z 238.10 (M+, 9%), 106.05 (8), 105.05 (100), 77.05 (34);
1
118.10 (14); Compound 21: H NMR (600 MHz, CDC3) d 7.36–7.33 (2H, m, H200
and H600), 7.31–7.27 (2H, m, H300 and H500), 7.23–7.19 (1H, m, H400), 7.05 (1H, d,
J = 8.33 Hz, H3), 6.50 (2H, br d, J = 13.92 Hz, H30), 6.47 (1H, dd, J = 8.33, 2.50 Hz,
H5), 6.43 (1H, d, J = 2.50 Hz, H6), 6.37 (1H, dt, J = 13.92, 6.50 Hz, H20), 3.78 (3H, s,
-OMe), 3.50 (2H, dd, J = 6.50, 1.31 Hz, H10a and H10b); HRMS (AP-) m/z Calcd for
HRMS (ES+) m/z Calcd for
C
16H15O2 [M+1]+ 239.1072. Found 239.1075.
1
Compound 6: H NMR (600 MHz, CDCl3) d 7.79–7.75 (2H, m, H-20, H-60), 7.44–
7.36 (3H, m, H30, H40 and H50), 7.25 (1H, dd, J = 7.53, 1.51, H3), 7.22–7.19 (1H, m,
H5), 7.13–7.09 (1H, m, H4), 7.06 (1H, dd, J = 7.96, 0.95, H6), 4.91 (1H, d, J = 2.57,
C
16H15O2 [M-1]ꢀ 239.1072. Found 239.1075.