K. Matcha, S. Ghosh / Tetrahedron Letters 51 (2010) 6924–6927
6927
111.0 (CH), 110.4 (CH), 87.8 (CH), 71.1 (CH2), 55.9 (CH3), 54.9 (CH3), 44.2
(CH), 42.9 (CH), 11.4 (CH3), 10.9 (CH3); HRMS (ESI) calcd for C21H26O4Na
References and notes
(M+Na)+: 365.1729. Found: 365.1729. Compound 18: ½a 2D5
ꢃ
15.6 (c 1.8, CHCl3);
1. Reviews: (a) Pan, J. Y.; Chen, S. L.; Yang, M. H.; Wu, J.; Sinkkonen, J.; Zou, K. Nat.
Prod. Rep. 2009, 26, 1251; (b) Saleem, M.; Kim, H. J.; Ali, M. S.; Lee, Y. S. Nat. Prod.
Rep. 2005, 22, 696; (c) Ward, R. S. Nat. Prod. Rep. 1995, 12, 183. and earlier
reviews in this series.
2. Vieira, L. M.; Kijjoa, A.; Silva, A. M. S.; Mondranondra, I.; Herz, W. Phytochemistry
1998, 48, 1079.
3. Crossley, N. S.; Djerassi, C. J. Chem. Soc. 1962, 1459.
4. Riggs, N. V.; Stevens, J. D. Aust. J. Chem. 1962, 15, 30.
5. Yeu, J. M.; Chen, Y. Z.; Hua, S. M.; Cheng, J. L.; Cui, Y. X. Phytochemistry 1989, 28,
1774.
6. (a) Ahmed, R.; Schrebier, F. G.; Stevenson, R. Tetrahedron 1976, 32, 1339; (b)
Esumi, T.; Hojyo, D.; Zhai, H.; Fukuyama, Y. Tetrahedron Lett. 2006, 47, 3979; (c)
Jahn, U.; Rudakov, D. Org. Lett. 2006, 8, 4481; (d) Kim, H.; Wooten, C. M.; Park, Y.;
Hong, J. Org. Lett. 2007, 9, 3965; (e) Hanessian, S.; Reddy, G. J. Synlett 2007, 475;
(f) Fukuyama, Y.; Harada, K.; Esumi, T.; Hojyo, D.; Kujime, Y.; Kubo, N.; Kubo, M.;
Hioki, H. Heterocycles 2008, 76, 551; (g) Rye, C. E.; Barker, D. Synlett 2009, 3315.
7. Matcha, K.; Ghosh, S. Tetrahedron Lett. 2008, 49, 3433.
IR mmax (liquid film) 2928, 1770, 1516, 1456 cmꢀ1 1H NMR (300 MHz, CDCl3)
;
d 7.44–7.30 (5H, m), 6.86 (1H, d, J = 8.3 Hz), 6.85 (1H, d, J = 2.0 Hz), 6.77 (1H,
dd, J = 1.8, 8.1 Hz), 5.15 (2H, m), 4.98 (1H, d, J = 6.8 Hz), 3.89 (3H, s), 2.78 (1H,
q, J = 7.7 Hz), 2.53 (1H, sixtet, J = 7.0 Hz), 1.22 (3H, d, J = 7.5 Hz), 1.07 (3H, d,
J = 7.0 Hz); 13C NMR (75 MHz, CDCl3) d 179.8 (CO), 150.1 (C), 148.5 (C), 137.0
(C), 131.3 (C), 128.7 (CH) (x2), 128.0 (CH), 127.4 (CH) (x2), 118.3 (CH), 113.9
(CH), 109.3 (CH), 85.8 (CH), 71.2 (CH2), 56.2 (CH3), 42.2 (CH), 38.5 (CH), 12.6
(CH3), 10.3 (CH3); HRMS (ESI) calcd for C20H22O4Na (M+Na)+: 349.1416.
Found: 349.1418. Compound 20: ½a D25
ꢃ
18.0 (c 0.9, CHCl3); 1H NMR (300 MHz,
CDCl3) d 7.05 (1H, d, J = 1.3 Hz), 7.0–6.85 (5H, m), 5.62 (1H, br s), 5.12 (1H, d,
J = 8.6 Hz), 4.40 (1H, d, J = 9.3 Hz), 3.91 (3H, s), 3.87 (3H, s), 3.85 (3H, s),
2.28–2.20 (1H, m), 1.84–1.74 (1H, m), 1.05 (3H, d, J = 6.5 Hz), 0.66 (3H, d,
J = 7.0 Hz); 13C NMR (75 MHz, CDCl3) d 148.7 (C), 148.2 (C), 146.6 (C), 145.3
(C), 133.9 (C), 132.9 (C), 119.4 (CH), 119.3 (CH), 114.3 (CH), 110.8 (CH), 110.5
(CH), 109.5 (CH), 87.5 (CH), 83.1 (CH), 56.0 (CH3) (x2), 55. 9 (CH3), 47.9 (CH),
46.1 (CH), 15.0 (CH3) (x2); HRMS (ESI) calcd for C21H26O5Na (M+Na)+:
381.1678. Found: 381.1675. Compound 2: ½a D25
ꢃ
33.9 (c 1.75, CHCl3); 1H NMR
8. Banerjee, S.; Ghosh, S.; Sinha, S.; Ghosh, S. J. Org. Chem. 2005, 70, 4199.
(300 MHz, CDCl3)
d 7.07–7.02 (2H, m), 6.89–6.82 (4H, m), 5.13 (1H, d,
9. All new compounds were characterized on the basis of IR, 1H, 13C NMR and
J = 8.5 Hz), 4.42 (1H, d, J = 9.2 Hz), 3.90 (3H, s), 3.89 (3H, s), 3.87 (3H, s), 3.85
(3H, s), 2.25 (1H, m), 1.79 (1H, m), 1.07 (3H, d, J = 6.5 Hz), 0.66 (3H, d,
HRMS data. Spectral data for selected compounds: Compound 13. ½a D25
ꢀ20.8
ꢃ
(c 3.7, CHCl3); IR mmax (liquid film) 1658, 1515 cmꢀ1 1H NMR (300 MHz,
;
J = 7.0 Hz); 13C NMR (75 MHz, CDCl3)
d 149.1 (C), 148.72 (C), 148.71 (C),
CDCl3) d 7.44–7.25 (5H, m), 6.99 (1H, s), 6.83–6.75 (2H, m), 5.14 (2H, s), 4.70
(1H, s), 4.50 (1H, d, J = 9.6 Hz), 3.90 (3H, s), 3.48 (3H, s), 2.42 (1H, dd, q,
J = 9.6, 7.2, 6.6), 2.25 (1H, q, J = 7.1 Hz), 1.00 (3H, d, J = 7.3 Hz), 0.91 (3H, d,
J = 6.8 Hz); 13C NMR (75 MHz, CDCl3) d 149.9 (C), 147.8 (C), 137.4 (C), 135.5
(C), 128.6 (CH) (x2), 127.8 (CH), 127.3 (CH) (x2), 119.4 (CH), 113.5 (CH),
148.2 (C), 133.9 (C), 133.6 (C), 119.3 (CH), 118.8 (CH), 111.1 (CH), 110.8 (CH),
110.5 (CH), 110.1 (CH), 87.4 (CH), 83.1 (CH), 56.08 (CH3), 56.00 (CH3) (x2),
55.94 (CH3), 48.0 (CH), 46.1 (CH), 15.18 (CH3), 15.11 (CH3); HRMS (ESI) calcd
for C22H28O5Na (M+Na)+: 395.1834. Found: 395.1835.