R. Settambolo et al. / Tetrahedron: Asymmetry 14 (2003) 2491–2493
2493
Acknowledgements
9. The pyrrolyl esters 2a–b showed spectroscopic data simi-
lar to those reported in literature.8a–c Selected data for 2c:
colorless liquid, bp 80°C at P=0.1 mmHg, [h]2D6=+4.02
(c 2.3, MeOH). 1H NMR (CDCl3, 200 MHz, TMS) l
6.74 (t, J=2.2 Hz, 2H), 6.17 (t, J=2.2 Hz, 2H), 4.57 (dd,
J=6.4; 9.1 Hz, 1H), 3.71 (s, 3H), 2.04 (m, 2H), 1.25 (m,
2H), 0.92 (t, J=9.0 Hz, 3H). MS m/e 181 (M+ 58), 139
(32), 122 (100), 107 (40), 94 (10), 80 (75), 68 (13).
10. Polt, R.; Peterson, M. A.; DeYoung, L. J. Org. Chem.
1992, 57, 5469 and references cited therein.
Financial support by MIUR is gratefully acknowl-
edged.
References
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(Scheme 1).
7. (a) Smith, E. L.; Polglase, W. J. J. Biol. Chem. 1949, 180,
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11. Settambolo, R.; Caiazzo, A.; Lazzaroni, R. J.
Organomet. Chem. 1996, 506, 337.
12. Spectroscopic data for 3a were in accord with those
reported in literature:8c,11 [h]2D6=+70.8 (c 0.99, benzene).
Selected data for 3b: colorless liquid, bp 60°C at P=0.01
mmHg, [h]2D6=−59.4 (c 1.1, benzene). H NMR (CDCl3,
1
200 MHz, TMS) l 9.75 (d, J=1.8 Hz, 1H), 6.70 (t,
J=2.2 Hz, 2H), 6.27 (t, J=2.2 Hz, 2H), 4.13 (dd, J=2.2;
8.8 Hz, 1H), 2.46 (m, 1H), 1.08 (d, J=7.0 Hz, 3H), 0.86
(d, J=6.8 Hz, 3H). MS m/e 151 (M+ 49), 122 (100), 108
(32), 94 (18), 80 (70), 68 (32), 55 (50). Selected data for
3c: colorless liquid, bp 65°C at P=0.02 mmHg, [h]2D6=
+44.4 (c 1.05, benzene). 1H NMR (CDCl3, 200 MHz,
TMS) 9.63 (d, J=1.0 Hz, 1H), 6.67 (t, J=2.1 Hz, 2H),
6.26 (t, J=2.1 Hz, 2H), 4.42 (dd, J=4.8; 9.5 Hz, 1H),
1.96 (m, 2H), 1.28 (m, 2H), 0.95 (t, J=7.0 Hz, 3H). MS
m/e 151 (M+ 36), 122 (78), 84 (20), 80 (100), 68 (20).
13. The spectral data for 4a were in accord with those
reported in literature.4b,5d [h]2D6=−62.5 (c 0.52, MeOH).
Selected data for 4b: as a colorless liquid, bp 80°C at
P=0.05 mmHg. [h]D26=−88.9 (c 1.5, MeOH). 1H NMR
(CDCl3, 200 MHz, TMS) l 6.67 (t, J=2.2 Hz, 2H), 6.15
(t, J=2.2 Hz, 2H), 6.04 (m, 1H), 5.16 (m, 2H), 3.99 (t,
J=8.2, 1H), 2.08 (m, 1H), 0.97 (d, J=6.6 Hz, 3H), 0.78
(d, J=6.6 Hz, 3H). MS m/e 149 (M+ 37), 106 (100), 79
(27), 67 (21), 55 (10). Selected data for 4c: as a colorless
liquid, bp 50°C at P=0.02 mmHg. [h]2D6=−58.5 (c 1.1,
MeOH). 1H NMR (CDCl3, 200 MHz, TMS) l 6.69 (t,
J=2.1 Hz, 2H), 6.16 (t, J=2.1 Hz, 2H), 5.97 (m, 1H),
5.09 (m, 2H), 4.43 (m, 1H), 1.82 (m, 2H), 1.26 (m, 2H),
0.92 (t, J=7.4 Hz, 3H). MS m/e 149 (M+ 60), 120 (8), 106
(100), 81 (24), 67 (52), 55 (20).
14. Jurczak, J.; Golebiowski, A. Chem. Rev. 1989, 89, 149
and references cited therein.