LETTER
Diels–Alder Reaction of 2-Nitro Glycals
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(4) (a) Yang, J.; Fan, S.; Pei, H.; Zhu, B.; Xu, W.; Naganawa,
H.; Hamada, M.; Takeuchi, T. J. Antibiot. 1991, 44, 1277.
(b) Suetsuna, K.; Osajima, Y. Agric. Biol. Chem. 1989, 53,
241.
(5) Hanessian, S. Deoxy Sugars; American Chemical Society:
Washington DC., 1968.
(6) Burnouf, C.; Lopez, J. C.; Calvo-Flores, F. G.; De los
Angeles Laborde, M.; Olesker, A.; Lukacs, G. J. Chem. Soc.,
Chem. Commun. 1990, 823.
(7) (a) Dötz, K. H.; Ehlenz, R.; Paetsch, D. Angew. Chem. Int.
Ed. Engl. 1997, 36, 2376. (b) Hallett, M. R.; Painter, J. E.;
Ricketts, D. Tetrahedron Lett. 1998, 39, 2851.
(8) (a) Das, J.; Schmidt, R. R. Eur. J. Org. Chem. 1998, 1609.
(b) Winterfeld, G. A.; Ito, Y.; Ogawa, T.; Schmidt, R. R.
Eur. J. Org. Chem. 1999, 1167. (c) Winterfeld, G. A.;
Khodair, A. I.; Schmidt, R. R. Eur. J. Org. Chem. 2003,
1009. (d) Khodair, A. I.; Schmidt, R. R. Eur. J. Org. Chem.,
in print. (e) Pachamuthu, K.; Gupta, A.; Das, J.; Schmidt, R.
R.; Vankar, Y. D. Eur. J. Org. Chem. 2002, 1479.
(f) Winterfeld, G. A.; Das, J.; Schmidt, R. R. Eur. J. Org.
Chem. 2000, 3047.
127.6, 127.7, 127.9, 128.2, 128.3, 129.1, 130.5, 137.5,
137.8, 156.1. MALDI: m/z 507 (M + Na+). Calcd: C, 76.80;
H, 6.66. Found: C, 76.55; H, 6.39.
6: [a]D20 = +6.3 (c 1, CHCl3); 1H NMR (250 MHz): d 3.71–
3.83 (m, 2 H), 4.14 (dd, J = 2.2 Hz, 3.2 Hz, 1 H), 4.34 (td,
J = 1.4 Hz, 5.9 Hz, 1 H), 4.44 (d, J= 11.9 Hz, 1 H), 4.53 (d,
J = 11.9 Hz, 1 H), 4.57–4.86 (m, 5 H), 5.14 (br s, 1 H), 6.29
(d, J = 2.4 Hz, 1 H), 6.39 (dd, J = 2.5 Hz, 8.3 Hz, 1 H), 7.20–
7.40 (m, 16 H). 13C NMR (62.9 MHz): d 69.1, 70.1, 71.8,
73.1, 73.5, 74.0, 75.8, 103.1, 108.6, 114.0, 127.7, 127.8,
128.1, 128.3, 128.4, 129.3, 137.7, 138.1, 153.9, 156.7.
MALDI: m/z 505 (M + Na+). Calcd: C, 77.16; H, 6.27.
Found: C, 76.82; H, 6.57.
9: [a]D20 = +26.7 (c 1, CHCl3); 1H NMR (250 MHz): d 3.7–
3.89 (m, 2 H), 4.04 (t, J = 6.1 Hz, 1 H), 4.29–4.35 (m, 1 H),
4.58–4.80 (m, 7 H), 5.4 (br s, 1 H), 6.34 (d, J = 2.43 Hz, 1
H), 6.4 (dd, J = 2.44 Hz, 8.34 Hz, 1 H), 7.1 (d, J = 8.38 Hz,
1 H), 7.23–7.37 (m, 15 H). 13C NMR (62.9 MHz): d 69.0,
71.2, 73.1, 73.5, 73.6, 76.1, 77.01, 103.3, 109, 113.9, 127.7,
127.9, 128.0, 128.5, 130.2, 137.8, 138.2, 154.6, 156.7.
MALDI: m/z 505(M + Na+).
(9) (a) Lemieux, R. U.; Nagabushan, T. L.; O’Neill, I. K.
Tetrahedron Lett. 1964, 5, 1909. (b) Lemieux, R. U.;
Nagabushan, T. L.; O’Neill, I. K. Can. J. Chem. 1968, 46,
413.
(10) Kraus, G. A.; Thurston, J.; Thomas, P. J. Tetrahedron Lett.
1988, 29, 1879.
10: [a]D20 = +30.1 (c 1, CHCl3); 1H NMR (250 MHz): d
3.53–3.92 (m, 6 H), 4.35–4.92(m, 17 H), 5.18 (br s, 1 H),
5.34 (d, J = 3.6 Hz, 1 H), 6.37 (d, J = 2.18 Hz, 1 H), 6.42 (dd,
J = 2.32 Hz, 8.24 Hz, 1 H), 7.12 (dd, J = 3.26 Hz, 7.06 Hz, 1
H), 7.24–7.30 (m, 30 H). 13C NMR (62.9 MHz): d 68.4, 69.0,
69.4, 70.9, 72.9, 73.3, 73.4, 74.5, 75.0, 75.5, 76.9, 80.0, 81.7,
96.1, 103.7, 109.1, 112.7, 127.6, 127.7, 127.8, 127.9, 128.3,
128.4, 131.1, 137.9, 138.0, 138.1, 138.3, 138.8, 154.9,
156.9. MALDI: m/z 937 (M + Na+).
(11) Corey, E. J.; Estreicher, H. Tetrahedron Lett. 1981, 22, 603.
(12) General experimental procedure for 6, 9, 10 and 12: A
solution of 2-nitro glycal (1 mmol) and Danishefky’s diene
(1.1 mmol) in dry toluene (2 mL) was refluxed under argon
for 36 h. The reaction mixture was allowed to cool and the
toluene was removed under reduced pressure. Then a
mixture of THF–10% H2SO4 in H2O (2:1) was added and
stirred at room temperature for 30 min. The product was
isolated by extractive workup followed by filtration by
column chromatography. The hydrolyzed product was
dissolved in 1 M NaOCH3 in methanol (2 mL) and heated at
50 °C for 1.5 h. Methanol was evaporated followed by
neutralization with saturated aq NH4Cl solution and
extracted with ethyl acetate. The organic layer was washed
with water, brine and dried over anhydrous MgSO4.
Evaporation of the solvent yielded the benzannulated
pyrans.
12: [a]D20 = –27.1 (c 1, CHCl3); 1H NMR (250 MHz): d 1.46
(d, J = 6.48 Hz, 3 H), 3.69 (dd, J = 6.83 Hz, 8.08 Hz, 1 H),
4.11–4.19 (m, 1 H), 4.65–4.88 (m, 6 H), 6.27 (d, J = 2.48 Hz,
1 H), 6.40 (dd, J = 2.51 Hz, 8.39 Hz, 1 H), 7.15 (dd, J = 0.64
Hz, 8.41 Hz, 1 H), 7.23–7.36 (m, 10 H). 13C NMR (62.9
MHz): d 17.9, 71.5, 73.7, 74.4, 77.3, 79.1, 102.9, 109.0,
114.7, 127.7, 127.87, 127.89, 127.9, 128.5, 129.8, 137.8,
138.2, 155.0, 156.5. Cald: C, 76.57; H, 6.43. Found: C,
76.25; H, 6.32.
15: [a]D20 = +53.6 (c 0.5, CHCl3); 1H NMR (600 MHz): d
2.02, 2.12 (2 s, 6 H), 2.25–2.33 (m, 1 H), 2.4–2.5 (m, 1 H),
2.9 (t, J = 6.7 Hz, 1 H), 3.77 (s, 3 H), 4.2–4.35 (m, 3 H),
5.08–5.17 (m, 3 H), 5.8–5.9 (m, 1 H), 6.46 (d, J = 1 Hz, 1 H),
6.53 (dd, J = 2.5 Hz, 8.4 Hz, 1 H), 6.98 (d, J = 8.5 Hz, 1 H).
13C NMR (150.8 MHz): d 20.8, 21.0, 38.4, 41.5, 55.3, 63.3,
68.0, 69.9, 101.2, 108.5, 118.0, 130.5, 134.8, 153.5, 159.4,
170.4, 170.7. Calcd: C, 64.66; H, 6.63. Found: C, 64.95; H,
7.0.
For compound 5: A mixture of hydrolyzed products 3 and 4
and DBN (3 equiv) in toluene (2 mL) was refluxed for 24 h.
The reaction mixture was neutralized with aq NH4Cl after
removal of the toluene followed by extraction with ethyl
acetate. The organic layer was washed with dilute HCl,
water, brine and dried over anhydrous MgSO4. Evaporation
of the solvent and purification by column chromatography
yielded the product 5 in 68% yield.
17: [a]D20 = +29.6 (c 1, CHCl3); 1H NMR (250 MHz): d 1.98,
2.0, 2.1 (3 s, 9H), 2.77 (d, J = 6.9 Hz, 2 H), 3.75 (s, 3 H), 4.07
(dd, J = 6.8 Hz, 11.8 Hz, 1 H), 4.23 (dd, J = 4.6 Hz, 11.8 Hz,
1 H), 5.13–5.26 (m, 2 H), 6.92–7.2 (m, 4 H). 13C NMR (62.9
MHz): d 20.6, 20.7, 21.0, 36.2, 62.2, 70.6, 72.0, 121.6,
130.2, 133.6, 149.6, 169.3, 170.0, 170.4.
Some selected data:
5: [a]D20 = –39.1 (c 1, CHCl3); 1H NMR (250 MHz): d 2.86
(br s, 1 H), 3.45–3.55 (m, 2 H), 3.59 (dd, J = 1.99, 7.82 Hz,
1 H), 3.93 (d, J = 10.8 Hz, 1 H), 4.09 (d, J = 10.8 Hz, 1 H),
4.19 (br s, 1 H), 4.25 (d, J = 11.46 Hz, 1 H), 4.44 (d, J = 11.46
Hz, 1 H), 4.43–4.54 (m, 3 H), 5.37 (br s, 1 H), 6.81–6.85 (m,
2 H), 6.93–6.97 (m, 2 H), 7.18–7.35 (m, 15 H). 13C NMR
(62.9 MHz): d 69.7, 70.4, 71.2, 73.3, 73.9, 80.3, 81.1, 115.4,
(13) Dufner, G. Ph.D. Dissertation; Universität Konstanz:
Germany, 1997.
(14) Iida, H.; Tamazaki, N.; Kibayashi, C. J. Org. Chem. 1987,
52, 1956.
(15) Sunazuka, T.; Tabata, N.; Nagamitsu, T.; Tomoda, H.;
Omura, S. Tetrahedron Lett. 1993, 34, 6659.
Synlett 2003, No. 9, 1355–1357 ISSN 1234-567-89 © Thieme Stuttgart · New York