Diastereoselective formation of cyclic acetals via an intramolecular fluoride-catalyzed hetero-Michael reaction

Tetrahedron Letters

Volumn 37, Issue 17, 1996, Pages 2927-2930

  Evans, P Andrew ^a   Garber, Lisa T ^a  

^a UNIVERSITY OF DELAWARE   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

1,3 DIOXANE DERIVATIVE; 1,3 DIOXOLANE DERIVATIVE;

ARTICLE; DRUG SYNTHESIS; REACTION ANALYSIS; STEREOCHEMISTRY;

STAPHYLOCOCCUS PHAGE 3A;

EID: 0029920463     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/0040-4039(96)00449-2     Document Type: Article

References (16)

1. For a recent review on cyclic acetals, see Alexakis, A.; Mangeney, P. Tetrahedron: Asymmetry 1990, 7, 477.
2. Kunz, H.; Waldmann, H. in Comprehensive Organic Synthesis, Trost, B. M. and Fleming, I., Eds.; Pergamon Press, New York, 1991, Vol. 6, pp 659-662.
3. Denmark, S. E.; Almstead, N. G. J. Am. Chem. Soc. 1991, 113, 8089. Sammakia, T.; Smith, R. S. J. Am. Chem. Soc. 1992, 114, 10998. Andrus, M. B.; Lepore, S. D. Tetrahedron Lett. 1995, 36, 9149 and references cited therein.
4. Denmark, S. E.; Almstead, N. G. J. Am. Chem. Soc. 1991, 113, 8089. Sammakia, T.; Smith, R. S. J. Am. Chem. Soc. 1992, 114, 10998. Andrus, M. B.; Lepore, S. D. Tetrahedron Lett. 1995, 36, 9149 and references cited therein.
5. Denmark, S. E.; Almstead, N. G. J. Am. Chem. Soc. 1991, 113, 8089. Sammakia, T.; Smith, R. S. J. Am. Chem. Soc. 1992, 114, 10998. Andrus, M. B.; Lepore, S. D. Tetrahedron Lett. 1995, 36, 9149 and references cited therein.
6. Rychnovsky, S. D.; Skalitsky, D. J. J. Org. Chem. 1992, 57, 4336 and references cited therein.
7. Omura, S.; Tanaka, H. in Macrolide Antibiotics: Chemistry, Biology and Practice, Omura, S. Ed.; Academic Press, New York, 1984, pp 351-404.
8. Gordillo, B.; Juaristi, E.; Martínez, R.; Toscano, R. A.; White, P. S.; Eliel, E. L. J. Am. Chem. Soc. 1992, 114, 2157 and references cited therein.
9. For an example of a fluoride induced hetero-Michael reaction for the synthesis of cyclic ethers, see: Palazón, J. M.; Soler, M. A.; Ramírez, M. A.; Martin, V. S. Tetrahedron Lett. 1993, 34, 5471.
10. For an example of the synthesis of syn-1,3-benzylidene acetals using a hetero-Michael reaction, see: Evans, D. A.; Gauchet-Prunet, J. A. J. Org. Chem. 1993, 58, 2446.
11. The vinylogous carbonates 1a-g were prepared, in 78-91% yield, from the corresponding secondary alcohols using tributylphosphine and methyl propiolate at room temperature: Inanaga, J.; Baba, Y.; Hanamoto, T. Chem. Lett. 1993, 241.
12. 13C-NMR) and analytical (HRMS) data in accord with the assigned structure.
13. b for the 5-, 6-and 7-membered cyclic acetals. Formula Represented
14. 4, filtered and the solvent removed in vacuo to afford a crude yellow oil. Purification by flash chromatography (eluting with 1:4 diethyl ether/hexane) afforded the cyclic acetal 2e (0.102 g, 90%) as a colorless oil.
15. Molecular mechanics as implemented on the Tektronix CAChe workstation for 2,4-dimethy 1-1,3-dioxolane 5 confirm the cis-isomer to be the most stable diastereoisomer. However, the relatively small experimental difference between the two diastereoisomers may be attributed to electronic factors not considered in the calculations. Formula Represented
16. 2