Communications
the enantiomer of that depicted by Suenaga et al. because of the
commercial availability of only the S enantiomer of 2-methyl-
butanol, which we used to gain access to the remote C18
stereocenter.
Table 1: Selected physical properties for 17, 27, and 1.
17: Rf =0.25 (silica gel, Et2O/CH2Cl2 15:85); [a]2D0 =+107.58 (c=0.4,
CH2Cl2); IR (film): n˜ =3478, 1732, 1669, 1624, 1462, 1387, 1371, 1294,
1166, 1095, 1058, 1038, 1010, 986, 918 cmꢀ1; 1H NMR (600 MHz, C6D6):
d=4.93 (t, J=3.6 Hz, 1H), 3.83 (dd, J=10.2, 2.4 Hz, 1H), 3.49 (dd,
10.8, J=5.4 Hz, 1H), 3.37–3.34 (m, 1H), 2.50–2.44 (m, 1H), 2.43 (q,
J=6.6 Hz, 1H), 2.20–2.13 (m, 3H), 1.89 (s, 3H), 1.87 (qd, J=7.2,
4.2 Hz, 1H), 1.81–1.73 (m, 2H), 1.61–1.55 (m, 1H), 1.54–1.40 (m, 2H),
1.14 (d, J=6.6 Hz, 3H), 1.06 (d, J=6.6 Hz, 3H), 0.89 (d, J=6.0 Hz,
3H), 0.88 (t, J=7.8 Hz, 3H), 0.88 (d, J=6.0 Hz, 3H), 0.80 (d, J=7.2 Hz,
3H), 0.67 (d, J=7.2 Hz, 3H), 0.56 ppm (d, J=7.2 Hz, 3H); 13C NMR
(75.5 MHz, C6D6): d=192.8, 172.0, 167.3, 108.0, 105.3, 75.1, 71.8, 66.6,
44.6, 44.0, 37.7, 36.6, 34.2, 31.9, 27.4, 26.3, 22.4, 22.3, 16.6, 12.6, 12.4,
12.0, 10.0, 9.4, 8.0 ppm; HR ESI MS: calcd for C25H42O6Na+ [M+Na+]:
461.2874; found: 461.2879; EI MS m/z (%): 197 (15), 149 (22), 111 (17),
97 (30), 85 (55), 83 (67), 72 (51), 70 (59), 57 (100), 55 (71).
[4] D. A. Evans, J. R. Gage, Org. Synth. 1989, 68, 77 – 91; D. A.
Evans, M. D. Ennis, T. Le, J. Am. Chem. Soc. 1984, 106, 1154 –
1156; D. A. Evans, H. P. Ng, J. S. Clark, D. L. Rieger, Tetrahe-
dron 1992, 48, 2127 – 2142.
[5] R. D. Walkup, R. J. Kane, P. D. Boatman, Jr., R. T. Cunningham,
Tetrahedron Lett. 1990, 31, 7587 – 7590; D. W. Jeffery, M. V.
Perkins, Tetrahedron Lett. 2004, 45, 8667 – 8671.
[6] M. V. Perkins, S. Jahangiri, M. R. Taylor, Tetrahedron Lett. 2006,
47, 2025 – 2028; M. V. Perkins, R. A. Sampson, J. Joannou, M. R.
Taylor, Tetrahedron Lett. 2006, in press..
[7] D. A. Evans, J. S. Clark, R. Metternich, V. J. Novack, G. S.
Sheppard, J. Am. Chem. Soc. 1990, 112, 866 – 868.
[8] Y. Oikawa, T. Nishi, O. Yonemitsu, Tetrahedron Lett. 1983, 24,
4037 – 4040; L. A. Paquette, M. Duan, I. Konetzki, C. Kemp-
mann, J. Am. Chem. Soc. 2002, 124, 4257 – 4270.
[9] I. Paterson, D. Y. Chen, J. L. Aceæa, A. S. Franklin, Org. Lett.
2000, 2, 1513 – 1516; M. Hikotam, Y. Sakurai, K. Horita, O.
Yonemitsu, Tetrehedron Lett. 1990, 31, 6367 – 6370; J. Inanaga,
K. Hirata, H. Saeki, T. Katsuki, M. Yamaguchi, Bull. Chem. Soc.
Jpn. 1979, 52, 1989 – 1993.
[10] D. A. Evans, A. M. Ratz, B. E. Huff, G. S. Sheppard, J. Am.
Chem. Soc. 1995, 117, 3448 – 3467.
[11] D. B. Dess, J. C. Martin, J. Org. Chem. 1983, 48, 4155 – 4156;
D. B. Dess, J. C. Martin, J. Am. Chem. Soc. 1991, 113, 7277 –
7287.
27: Rf =0.26 (silica gel, Et2O/CH2Cl2 20:80); [a]2D0 =+76.98 (c=0.4,
CH2Cl2); IR (film): n˜ =3505, 1734, 1670, 1620, 1459, 1388, 1373, 1346,
1294, 1254, 1212, 1166, 1120, 1094, 1058, 1009, 986, 964, 918 cmꢀ1
;
1H NMR (600 MHz, C6D6): d=4.96 (t, J=3.6 Hz, 1H), 4.15 (br s, 1H),
3.98 (dd, J=10.2, 1.8 Hz, 1H), 3.77 (br m, 1H), 2.81 (br s, 1H), 2.63 (qd,
J=7.2, 4.2 Hz, 1H), 2.53–2.43 (m, 3H), 2.39 (q, J=6.6 Hz, 1H), 2.24–
2.16 (m, 3H), 1.95–1.84 (m, 3H), 1.84 (s, 3H), 1.61–1.55 (m, 1H), 1.55–
1.50 (m, 1H), 1.49–1.43 (m, 1H), 1.37–1.31 (m, 1H), 1.14 (d, J=7.2 Hz,
3H), 1.08 (d, J=6.6 Hz, 3H), 1.07 (d, J=6.6 Hz, 3H), 1.03 (d,
J=7.2 Hz, 3H), 0.99 (t, J=7.2 Hz, 3H), 0.94 (t, J=7.2 Hz, 3H), 0.92 (d,
J=6.0 Hz, 3H), 0.91 (d, J=6.0 Hz, 3H), 0.80 (d, J=6.6 Hz, 3H), 0.76
(d, J=6.6 Hz, 3H), 0.76 ppm (d, J=7.2 Hz, 3H); 13C NMR (75.5 MHz,
CDCl3): d=220.2, 194.0, 172.1, 168.4, 107.5, 105.5, 75.2, 73.8, 70.3, 68.8,
50.5, 49.6, 44.5, 44.0, 38.2, 37.9, 34.1, 32.0, 27.6, 27.1, 26.3, 22.5, 22.4,
16.6, 12.4, 12.0, 11.0, 10.9, 10.7, 9.9, 9.8, 9.3, 7.9 ppm; HR ESI MS: calcd
for C33H56O8Na+ [M+Na+]: 603.3867; found: 603.3863; EI MS m/z (%):
197 (52), 168 (9), 139 (14), 109 (15), 85 (24), 57 (100).
[12] S. D. Rychnovsky, D. J. Skalitzky, Tetrahedron Lett. 1990, 31,
945 – 948.
´
[13] D. A. Evans, F. Urpy’, T. C. Somers, J. S. Clark, M. T. Bilodeau, J.
Am. Chem. Soc. 1990, 112, 8215 – 8216; D. A. Evans, D. L.
Rieger, M. T. Bilodeau, F. Urpi, J. Am. Chem. Soc. 1991, 113,
1047 – 1049; D. A. Evans, M. J. Dart, J. L. Duffy, D. L. Rieger, J.
Am. Chem. Soc. 1995, 117, 9073 – 9074.
1: m.p.: 171–1738C (172–1768C)[2]; Rf =0.27 (silica gel, Et2O/CH2Cl2
50:50); [a]2D0 =+33.38 (c=0.2, CHCl3); IR (film): n˜ =1729, 1656, 1626,
1618, 1459, 1419, 1386, 1374, 1291, 1251, 1166, 1091, 1058, 1010, 984,
963, 919 cmꢀ1; UV/Vis (MeOH) lmax (e): 260 (18200), 220 nm
[14] W. R. Roush, J. Org. Chem. 1991, 56, 4151 – 4157.
[15] P. A. McCarthy, M. Kageyama, J. Org. Chem. 1987, 52, 4681 –
4686; D. A. Evans, M. G. Yang, M. J. Dart, J. L. Duffy, Tetrahe-
dron Lett. 1996, 37, 1957 – 1960.
[16] J. J. Young, L. J. Jung, K. M. Cheng, Tetrahedron Lett. 2000, 41,
3411 – 3413; S. V. Ley, I. R. Baxendale, R. N. Bream, P. S.
Jackson, A. G. Leach, D. A. Longbottom, M. Nesi, J. S. Scott,
R. I. Storer, S. J. Taylor, J. Chem. Soc. Perkin Trans. 1 2000,
3815 – 4195; M. V. Perkins, W. Kitching, R. A. I. Drew, C. J.
Moore, W. A. Konig, J. Chem. Soc. Perkin Trans. 1 1990, 1111 –
1117.
[17] A small amount of an inseparable isomer ( ꢁ 6%) was present in
the purified product; this contaminant was carried through the
synthesis and is seen as a minor impurity in the spectra of the
final product auripyrone A.
[18] The major product was predicted and found to be the isomer in
which both oxygen atoms are in the anomerically favorable axial
positions; see P. Deslongchamps, D. D. Rowan, N. Pothier, T.
Sauve, J. K. Saunders, Can. J. Chem. 1981, 59, 1105 – 1121.
[19] A. Basha, M. Lipton, S. M. Weinreb, Tetrahedron Lett. 1977, 18,
4171 – 4174; D. A. Evans, A. S. Kim, R. Metternich, V. J. Novack,
J. Am. Chem. Soc. 1998, 120, 5921 – 5942.
1
(10100 mꢀ1cmꢀ1); H NMR (600 MHz, C6D6): d=4.92 (t, J=3.3 Hz,
1H), 3.98 (dd, J=10.2, 2.1 Hz), 2.76 (dq, J=10.2, 7.2 Hz, 1H), 2.32 (q,
J=6.6 Hz, 1H), 2.31 (dq, J=15.0, 7.5 Hz, 1H), 2.26 (dqd, J=7.2, 7.2,
3.6 Hz, 1H), 2.21–2.16 (m, 1H), 2.18–2.11 (m, 2H), 2.10 (dq, J=15.0,
7.5 Hz, 1H), 2.03 (s, 3H), 1.98 (s, 3H), 1.85 (qd, J=7.2, 3.6 Hz, 1H),
1.83–1.80 (m, 1H), 1.64 (s, 3H), 1.56–1.48 (m, 1H), 1.41–1.34 (m, 1H),
1.12 (d, J=6.6 Hz, 3H), 0.99 (d, J=7.2 Hz, 3H), 0.91 (d, J=6.0 Hz,
3H), 0.90 (d, J=6.6 Hz, 3H), 0.90 (t, J=7.5 Hz, 3H), 0.84 (t, J=7.5 Hz,
3H), 0.78 (d, J=7.2 Hz, 3H), 0.74 (d, J=7.2 Hz, 3H), 0.65 ppm (d,
J=7.2 Hz, 3H); 13C NMR (151 MHz, CDCl3): d=191.8, 178.5, 172.0,
166.2, 162.1, 161.6, 121.3, 118.1, 107.8, 105.0, 75.2, 70.6, 44.5, 44.0, 37.2,
36.7, 34.1, 31.7, 26.4, 26.3, 24.7, 22.5, 22.3, 16.0, 12.1, 12.0, 11.9, 11.0,
10.7, 9.7, 9.5, 8.9, 8.1 ppm; HR ESI MS: calcd for C33H50O7Na+
[M+Na+]: 581.3449; found: 581.3448; EI MS m/z (%): 558 (M+, 43), 501
(9), 457 (11), 391 (6), 317 (20), 261 (12), 221 (31), 193 (100), 180 (43),
151 (11), 137 (18), 85 (17), 83 (22), 57 (68), 55 (15).
[20] H. Arimoto, S. Nishiyama, S. Yamamura, Tetrahedron Lett. 1990,
31, 5619 – 5620.
[21] I. Paterson, A. S. Franklin, Tetrahedron Lett. 1994, 35, 6925 –
6928.
[22] H. Arimoto, R. Yokoyama, K. Nakamura, Y. Okumura, D.
Uemura, Tetrahedron 1996, 52, 13901 – 13908.
[23] D. W. Jeffery, M. V. Perkins, J. M. White, Org. Lett. 2005, 7, 407 –
409; D. W. Jeffery, M. V. Perkins, J. M. White, Org. Lett. 2005, 7,
1581 – 1584.
[1] K. Yamada, H. Kigoshi, Bull. Chem. Soc. Jpn. 1997, 70, 1479 –
1489; C. Tiringal, Bioactive Compounds from Natural Sources,
Taylor and Francis, London, 2001, pp. 580 – 621.
[2] K. Suenaga, H. Kigoshi, K. Yamada, Tetrahedron Lett. 1996, 37,
5151 – 5154.
[3] The structure drawn by Suenaga et al.[2] in the report on the
isolation of the natural product was an arbitrary choice for the
absolute stereochemistry of the auripyrones. We chose to target
2564
ꢀ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2006, 45, 2560 –2564