P. K. Sen et al. / Tetrahedron Letters 46 (2005) 8741–8743
8743
(d, J = 7.8 Hz, 1H); 13C NMR (75 MHz, CDCl3): d 19.8,
21.0, 25.1, 25.1, 29.8, 41.1, 51.2, 52.2, 78.5, 116.5, 122.1,
126.7, 132.9, 136.3, 152.5, 173.1, 175.0; HRMS (ES +ve)
calcd for C17H25O5 [M+H]+ 309.1703, found 309.1719. For
12: 1H NMR (300 MHz, CDCl3): d 1.16 (d, J = 6.5 Hz,
3H), 1.17 (s, 3H), 1.29 (s, 3H), 1.37–1.46 (m, 1H), 1.64–1.71
(m, 1H), 2.21 (s, 3H), 3.17–3.25 (m, 1H), 3.38–3.64 (m, 4H),
6.77 (s, 1H), 6.78 (d, J = 7.6 Hz, 1H), 7.01 (d, J = 7.6 Hz,
1H); 13C NMR (75 MHz, CDCl3): d 20.9, 21.6, 22.4, 24.3,
27.2, 42.5, 60.6, 71.1, 81.5, 122.8, 124.7, 126.8, 136.3, 137.4,
153.1; HRMS (ES +ve) calcd for C15H25O3 [M+H]+
References and notes
1. Bargellini, G. Gazz. Chim. Ital. 1906, 36, 329–339.
2. Weizmann, C.; Sulzbacher, M.; Bergmann, E. J. Am. Chem.
Soc. 1948, 70, 1153–1158.
3. Corey, E. J.; Barcza, S.; Klotmann, G. J. Am. Chem. Soc.
1969, 91, 4782–4786.
4. Macias, F. A.; Varela, R. M.; Torres, A.; Molinillo, J. M.
G.; Fronzek, F. R. Tetrahedron Lett. 1993, 34, 1999–
2002.
5. Harrison, B.; Crews, P. J. Org. Chem. 1997, 62, 2646–2648.
6. (a) Grimm, E. L.; Levac, S.; Trimble, L. A. Tetrahedron
Lett. 1994, 35, 6847–6850; (b) Stefinovic, M.; Snieckus, V.
J. Org. Chem. 1998, 63, 2808–2809.
253.1804, found 253.1797. For 13: IR (Neat) 1732 cmÀ1
;
1H NMR (300 MHz, CDCl3): d 1.28 (d, J = 6.9 Hz, 3H),
1.46 (s, 6H), 2.22 (s, 3H), 2.55–2.75 (m, 2H), 3.69–3.76 (m,
1H), 6.39 (s, 1H), 6.77 (d, J = 7.7 Hz, 1H), 7.07 (d,
J = 7.7 Hz, 1H), 9.69 (t, J = 1.9 Hz, 1H), 9.82 (s, 1H);
13C NMR (75 MHz, CDCl3): d 21.0, 21.8, 22.2, 22.4, 28.1,
51.3, 83.3, 117.1, 123.4, 127.7, 132.9, 137.4, 152.8, 202.6,
204.0. For 14: 1H NMR (300 MHz, CDCl3): d 1.18 (d,
J = 6.9 Hz, 3H), 1.48 (s, 6H), 2.10–2.43 (m, 2H), 2.25 (s,
3H), 3.20–3.27 (m, 1H), 4.93 (d, J = 11.3 Hz, 1H), 5.00 (d,
J = 18.8 Hz, 1H), 5.14 (d, J = 10.9 Hz, 1H), 5.22 (d,
J = 17.6 Hz, 1H), 5.69–5.89 (m, 1H), 6.16 (dd, J = 10.9,
17.6 Hz, 1H), 6.74 (d, J = 7.8 Hz, 1H), 6.86 (s, 1H), 7.04 (d,
J = 7.8 Hz, 1H); 13C NMR (75 MHz, CDCl3): d 20.6, 21.6,
27.8, 27.8, 32.4, 42.0, 79.6, 113.2, 115.7, 120.0, 122.5, 126.9,
135.8, 135.8, 138.3, 145.5, 153.9. For 15: 1H NMR
(300 MHz, CDCl3): d 1.26 (d, J = 6.9 Hz, 3H), 1.40(s,
3H), 1.62 (s, 3H), 2.29 (s, 3H), 2.85–3.43 (m, 3H), 5.27 (d,
J = 10.8 Hz, 1H), 5.61–5.74 (m, 1H), 6.75 (s, 1H), 6.88 (d,
J = 7.8 Hz, 1H), 6.98 (d, J = 7.8 Hz, 1H); 13C NMR
(75 MHz, CDCl3): d 21.3, 25.5, 28.9, 29.7, 29.8, 34.5,
81.6, 125.7, 127.9, 130.8, 131.2, 135.1, 136.0, 137.4; 152.9;
HRMS (ES +ve) calcd for C15H21O [M+H]+ 217.1593,
found 217.1587.
7. Tuhina, K.; Bhowmik, D. R.; Venkateswaran, R. V. Chem.
Commun. 2002, 634–635.
8. All new compounds reported here gave analytical and
spectral data consistent with the assigned structures. Select-
ed spectral data: For 7a: IR (KBr) 1695 (br), 1715,
2974 cmÀ1 1H NMR (300 MHz, CDCl3): d 1.59 (s, 6H),
;
2.17 (s, 3H), 2.29 (s, 3H), 5.99 (s, 1H), 6.53 (s, 1H), 6.80(d,
J = 7.8, 1H), 6.97 (d, J = 7.8 Hz, 1H); 13C NMR (75 MHz,
CDCl3): d 21.4, 24.8, 25.0, 27.1, 79.0, 116.5, 117.6, 122.3,
127.9, 128.4, 138.7, 150.3, 155.1, 169.8, 177.3; HRMS (ES
+ve) calcd for C15H19O5 [M+H]+ 279.1237, found
279.1236. For 10: IR (CHCl3) 1715, 1738 cmÀ1; H NMR
1
(300 MHz, CDCl3): d 1.52 (s, 6H), 2.16 (s, 3H), 2.28 (s, 3H),
3.55 (s, 3H), 3.75 (s, 3H), 5.91 (s, 1H), 6.53 (s, 1H), 6.78 (d,
J = 7.8 Hz, 1H), 6.92 (d, J = 7.8 Hz, 1H); 13C NMR
(75 MHz, CDCl3): d 21.3, 25.1, 25.9, 25.9, 50.6, 52.2,
79.2, 117.9, 118.1, 122.4, 128.3, 130.1, 138.1, 151.2, 154.4,
165.8, 174.9; HRMS (ES +ve) calcd for C17H23O5 [M+H]+
307.1546, found 307.1540. For 11: IR (CHCl3) 1738 cmÀ1
;
1H NMR (300 MHz, CDCl3): d 1.26 (d, J = 6.9 Hz, 3H),
1.63 (s, 6H), 2.24 (s, 3H), 2.45 (dd, J = 9.1, 15.0Hz, 1H),
2.70(dd, J = 5.5, 15.0Hz, 1H), 3.51–3.88 (m, 1H), 3.64 (s,
3H), 3.76 (s, 3H), 6.40(s, 1H), 6.73 (d, J = 7.8 Hz, 1H), 7.04
9. Sabui, S. K.; Venkateswaran, R. V. Tetrahedron Lett. 2004,
45, 9653–9655.