The effect of lithium iodide on the acid-promoted cyclization of 4-[(1-indolylcarbonyl)methyl]-1,4-dihydropyridines

Tetrahedron Letters

Volumn 37, Issue 42, 1996, Pages 7653-7656

  Bennasar, M Lluïsa ^a   Jiménez, Juan Miguel ^a   Sufi, Bilal A ^a   Bosch, Joan ^a  

^a UNIVERSITY OF BARCELONA   (Spain)

Author keywords

[No Author keywords available]

Indexed keywords

1,4 DIHYDROPYRIDINE DERIVATIVE; INDOLE DERIVATIVE;

ARTICLE; CYCLIZATION; DRUG SYNTHESIS; NUCLEAR MAGNETIC RESONANCE; REACTION ANALYSIS; STEREOCHEMISTRY;

EID: 0030583488     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/0040-4039(96)01703-0     Document Type: Article

References (17)

1. 1. Carbanion nucleophile additions to N-alkyl-β-acylpyridinium salts for alkaloid synthesis were first used by Wenkert: (a) Wenkert, E. Pure Appl. Chem. 1981, 53, 1271-1276.
2. (b) Wenkert, E.; Guo, M.; Pestchanker, M. J.; Shi, Y.-J.; Vankar, Y. D. J. Org. Chem. 1989, 54, 1166-1174 and references cited therein.
3. For reviews, see: (c) Bennasar, M.-L.; Lavilla, R.; Alvarez, M.; Bosch, J. Heterocycles 1988, 27, 789-824.
4. (d) Bosch, J.; Bennasar, M.-L. Synlett 1995, 587-596.
5. For more recent work, see: (e) Amann, R.; Spitzner, D. Angew. Chem., Int. Ed. Engl. 1991, 30, 1320-1321.
6. (f) Bennasar, M.-L.; Zulaica, E.; Ramírez, A.; Bosch, J. J. Org. Chem. 1996, 61, 1239-1251.
7. (g) Bennasar, M.-L.; Vidal, B.; Bosch, J. J. Org. Chem. 1996, 61, 1916-1917.
8. (h) Bennasar, M.-L.; Zulaica, E.; Sufi, B.A.; Bosch, J. Tetrahedron 1996, 52, 8601-8610.
9. 2. (a) Bennasar, M.-L.; Zulaica, E.; Bosch, J. J. Org. Chem. 1992, 57, 2835-2841.
10. (b) Bennasar, M.-L.; Vidal, B.; Bosch, J. J. Org. Chem. 1995, 60, 4280-4286.
11. 3. Massiot, G.; Delaude, C. In The Alkaloids; Brossi, A., Ed.; Academic Press: San Diego, 1988; Vol. 34, Chapter 5.
12. 13C-NMR 24.0 (MeCO), 28.4 (C-15), 30,0 (C-14), 41.5 (NMe), 44.4 (C-16), 51.6 (C-3), 110.0 (C-20), 110.5 (C-7), 114.5 (C-12), 120.2 (C-9), 123.0 (C-10), 124.0 (C-11), 129.0 (C-8), 137.5 (C-2), 139.4 (C-13), 146.2 (C-21), 171.1, 191.3 (CO).
13. 2CO), 50.7 (pyr C-2), 109.2 (indole C-3), 111.2 (pyr C-5), 111.7 (indole' C-7), 113.5 (indole' C-3), 116.5 (indole C-7), 119.0 (indole' C-4), 119.7 (indole' C-5), 120.6 (indole C-4), 122.6 (indole' C-6), 123.6 (indole C-5, indole' C-2), 124.6 (indole C-2), 125.5 (indole' C-3a), 127.0 (indole C-6), 130.6 (indole C-3a), 135.4 (indole' C-7a), 136.8 (indole C-7a), 150.5 (pyr C-6), 171.3, 192.9 (CO).
14. 6. All new compounds gave satisfactory spectral, analytical and/or HRMS data. All yields are from material purified by column chromatography.
15. 7. Bennasar, M.-L.; Zulaica, E.; Jiménez, J.-M.; Bosch, J. J. Org. Chem. 1993, 58, 7756-7767. See also references 1f and 2.
16. 8. For related ring-openings, see: (a) Wenkert, E.; Angell, E. C.; Drexler, J.; Moeller, P. D. R.; Pyrek, J. S.; Shi, Y.-J.; Sultana, M.; Vankar, Y. D. J. Org. Chem. 1986, 51, 2995-3000.
17. (b) Bennasar, M.-L.; Alvarez, M.; Lavilla, R.; Zulaica, E.; Bosch, J. J. Org. Chem. 1990, 55, 1156-1168. See also reference 7a.