J. B. Sperry, D. L. Wright / Tetrahedron 62 (2006) 6551–6557
6557
1
three times and the combined organic layers washed again
with 1 M HCl, water, saturated sodium bicarbonate, brine,
and dried over sodium sulfate. After concentrating, the prod-
uct was purified by flash chromatography (typical gradient
elution conditions were 20:1 hexanes/ethyl acetate/10:1
hexanes/ethyl acetate). Again, It is imperative that the silica
gel be degassed before chromatography to obtain reported
yields.
1505, 1107; H NMR (500 MHz) d 7.35–7.36 (m, 2H),
7.21–7.22 (m, 1H), 6.27 (s, 1H), 6.22 (d, J¼1.6 Hz, 1H),
3.03 (s, 1H), 2.39–2.47 (m, 6H), 1.97 (ddd, J¼13.2, 7.9,
5.1 Hz, 1H), 1.83–1.89 (m, 1H), 1.75 (dt, J¼13.7, 4.4 Hz,
1H), 1.57–1.69 (m, 4H) 1.37–1.44 (m, 1H); 13C NMR
(125 MHz) d 215.4, 145.2, 143.1, 142.9, 139.1, 124.9,
116.9, 111.0, 110.2, 55.0, 43.4, 37.4, 35.5, 31.0, 28.7,
25.5, 24.5, 19.0. EI-HRMS m/z calcd for C18H20O3 (M+):
284.1412; found: 284.1412.
4.5.2.1. cis-5a-Methyl-4,5,5a,6,7,8a-hexahydro-1-oxa-
as-indacen-8-one, 8. Isolated as a white solid (mp 42–
43 ꢁC, 74%); IR (KBr pellet) lmax (cmꢀ1) 2959, 2862,
4.5.2.6. cis-5a-(2-Thiophen-3-yl-ethyl)-4,5,5a,6,7,8a-
hexahydro-1-oxa-as-indacen-8-one, 48. Isolated as a
viscous, pale-yellow oil (1.00 g, 3.5 mmol, 76%), which so-
lidified in a ꢀ20 ꢁC freezer. IR (thin film) lmax (cmꢀ1): 3104,
2920, 2856, 1745, 1502, 1453; 1H NMR (500 MHz):
d 7.37 (dd, J¼1.9, 0.7 Hz, 1H), 7.26–7.27 (m, 1H), 6.94–
6.95 (m, 2H), 6.24 (d, J¼1.7 Hz, 1H), 3.10 (s, 1H), 2.71–
2.75 (m, 2H), 2.52–2.64 (m, 2H), 2.44–2.48 (m, 2H),
1.93–2.07 (m, 3H), 1.85 (dt, J¼13.9, 4.7 Hz, 1H), 1.64–
1.76 (m, 2H), 1.17–1.28 (m, 1H); 13C NMR (125 MHz):
d 215.1, 145.2, 143.0, 142.4, 128.3, 125.9, 120.2, 116.9,
110.3, 55.1, 43.5, 38.6, 35.6, 31.1, 28.6, 24.9, 19.1. EI-
HRMS m/z calcd for C17H18O2S: 286.1028; found:
286.1040.
1
1742, 1625, 1550, 1050; H NMR (300 MHz): d 7.35 (dd,
J¼1.9 Hz, 1H), 6.21 (J¼1.9 Hz, 1H), 3.00 (s, 1H), 2.51
(m, 2H), 2.41 (m, 2H), 2.00 (m, 1H), 1.81 (m, 1H), 1.62
(m, 2H), 1.19 (s, 3H); 13C NMR (125 MHz): d 215.1,
144.7, 142.6, 116.7, 110.0, 54.9, 40.2, 35.5, 33.1, 31.7,
25.5, 19.0. Anal. Calcd for C12H14O2: C, 75.76; H, 7.42;
found: C, 75.64; H, 7.51.
4.5.2.2. cis-6-Isopropyl-4,5a,6,7,8,9a-hexahydro-5H-
naphtho[1,2-b]furan-9-one, 11. Isolated as a colorless oil
that solidified in a ꢀ20 ꢁC freezer, (65%). IR (neat) lmax
(cmꢀ1): 2927, 1717, 1634, 1511; 1H NMR (500 MHz,
CDCl3) d 7.40 (dd, J¼2.0, 0.9 Hz, 1H), 6.21 (d, J¼2.0 Hz,
1H), 3.59 (d, J¼11.2 Hz, 1H), 2.43–2.60 (m, 4H), 2.10–
2.23 (m, 3H), 1.87 (qd, J¼11.5, 2.2 Hz, 1H), 1.78 (tt,
J¼11.5, 3.4 Hz, 1H), 1.54–1.63 (m, 1H), 1.39 (dddd,
J¼30.5, 24.4, 11.7, 5.6 Hz, 1H), 1.03 (d, J¼6.9 Hz, 3H),
0.80 (d, J¼7.1 Hz, 3H); 13C NMR: d 208.9, 146.8, 142.6,
119.4, 110.1, 52.9, 46.5, 46.1, 41.4, 27.4, 26.8, 26.5, 22.1,
21.7, 15.0. EI-HRMS m/z calcd for C15H20O2 (M+):
232.1463; found: 232.1465.
Acknowledgements
We are grateful to the National Science Foundation for sup-
port of this work.
References and notes
4.5.2.3.
cis-6a-Methyl-5,6,6a,7,8,9a-hexahydro-4H-
azuleno[4,5-b]furan-9-one, 17. Isolated as a colorless oil,
which solidified in a ꢀ20 ꢁC freezer, (61% carbon/stainless
steel, 70% RVC/carbon) IR (neat) lmax (cmꢀ1) 2930, 1715,
1. Wright, D. L. Prog. Heterocycl. Chem. 2005, x, 1.
2. Kawagishi, H.; Shimada, A.; Shirai, R.; Okamoto, K.; Ojima,
F.; Sakamoto, H.; Ishiguro, Y.; Furukawa, S. Tetrahedron
Lett. 1994, 35, 1569.
1
1631, 1505, 1251, 1107; H NMR (500 MHz) d 7.28 (d,
J¼1.7 Hz, 1H), 6.18 (d, J¼1.7 Hz, 1H), 3.37 (s, 1H),
2.49–2.55 (m, 1H), 2.43 (ddd, J¼8.7, 2.7, 1.0 Hz, 1H),
2.41 (dd, J¼10.6, 8.4 Hz, 1H), 2.31–2.36 (m, 1H), 1.84–
1.99 (m, 2H), 1.70–1.72 (m, 4H), 1.27 (s, 3H); 13C NMR
(125 MHz) d 215.4, 145.3, 141.3, 121.9, 113.4, 62.0, 40.2,
39.3, 37.6, 35.1, 26.1, 25.9, 22.5. EI-HRMS m/z calcd for
C13H16O2 (M+): 204.1150; found: 204.1137.
3. Tsukamoto, S.; Macabalang, A. D.; Nakatani, K.; Obara, Y.;
Nakahata, N.; Ohta, T. J. Nat. Prod. 2003, 66, 1578.
4. Carswell, S. Exp. Neurol. 1993, 124, 36.
5. Wright, D. L.; Whitehead, C. R.; Sessions, E. H.; Ghiviriga, I.;
Frey, D. A. Org. Lett. 1999, 1, 1535.
6. Whitehead, C. R.; Sessions, E. H.; Ghiviriga, I.; Wright, D. L.
Org. Lett. 2002, 4, 3763.
7. (a) Moeller, K. D.; New, D. G. Tetrahedron Lett. 1994, 35,
2857; (b) New, D. G.; Tesfai, Z.; Moeller, K. D. J. Org.
Chem. 1996, 61, 1578; For an excellent review see: Moeller,
K. D. Tetrahedron 2000, 56, 9527; For application in total syn-
thesis see: (c) Mihelcic, J.; Moeller, K. D. J. Am. Chem. Soc.
2003, 125, 36; (d) Mihelcic, J.; Moeller, K. D. J. Am. Chem.
Soc. 2004, 126, 9106.
4.5.2.4. cis-5a-Methyl-4,5,5a,6,7,8a-hexahydro-1-thia-
as-indacen-8-one, 24. Isolated as a white solid (mp 70.1–
70.8 ꢁC, 81%). IR (neat) lmax (cmꢀ1): 2922, 2855, 17,454,
1
1454, 1433, 1381; H NMR (500 MHz, CDCl3): d 7.19
(dd, J¼5.1, 0.5 Hz, 1H), 6.80 (dd, J¼5.1, 0.5 Hz, 1H),
3.04 (s, 1H), 2.68–2.71 (m, 2H), 2.39–2.47 (m, 2H), 2.02
(ddd, J¼17.5, 8.7, 4.4 Hz, 1H), 2.01 (dt, J¼13.1, 9.5 Hz,
1H), 1.60–1.72 (m, 2H), 1.24 (s, 3H); 13C NMR
(125 MHz): d 215.8, 134.3, 129.4, 126.6, 124.2, 56.5,
39.4, 35.2, 33.5, 31.2, 25.4, 22.4. Anal. Calcd for
C12H14OS: C, 69.86; H, 6.84; O, 7.76; S, 15.54; found: C,
69.83; H, 6.85; O, 7.78; S, 15.46.
8. Sperry, J. B.; Whitehead, C. R.; Ghiviriga, I.; Walczak, R. M.;
Wright, D. L. J. Org. Chem. 2004, 69, 3726.
9. Clayden, J.; Kenworthy, M. N. Org. Lett. 2002, 4, 787.
10. Sperry, J. B.; Wright, D. L. J. Am. Chem. Soc. 2005, 127, 8034.
11. (a) Zuman, P. Prog. Phys. Org. Chem. 1967, 5, 81; (b) Moeller,
K. D.; Tinao, L. V. J. Am. Chem. Soc. 1992, 114, 1033.
12. Nakayama, J.; Sugihara, Y. Top. Curr. Chem. 1999, 205, 131.
13. For related cases of Diels–Alder reactions on annulated furans
see: Sperry, J. B.; Constanzo, J. R.; Jasinski, J.; Butcher, R. J.;
Wright, D. L. Tetrahedron Lett. 2005, 46, 2789.
4.5.2.5. cis-5a-(3-Furan-3-yl-propyl)-4,5,5a,6,7,8a-
hexahydro-1-oxa-as-indacen-8-one, 46. Isolated as a vis-
cous colorless oil. IR (neat) lmax (cmꢀ1) 2933, 1717, 1630,