Alkoxide-catalyzed addition of terminal alkynes to ketones

Journal of Organic Chemistry

Volumn 61, Issue 1, 1996, Pages 416-417

  Babler, James H ^a   Liptak, Vincent P ^a   Phan, Nguyen ^a  

^a LOYOLA UNIVERSITY CHICAGO   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 5544290692     PISSN: 00223263     EISSN: None     Source Type: Journal    
DOI: 10.1021/jo9515283     Document Type: Article

References (11)

1. Viehe, H. G.; Reinstein, M. Chem. Ber. 1962, 95, 2657.
2. Eaton, P. E.; Srikrishna, A.; Uggeri, F. J. Org. Chem. 1984, 49, 1728.
3. Saunders, J. H. Organic Syntheses; Wiley: New York, 1955; Collect. Vol. III, p 416.
4. March, J. Advanced Organic Chemistry: Reactions, Mechanisms, and Structure; John Wiley & Sons: New York, 1992; Table 8.1, pp 250-2.
5. These patents are cited by Tedeschi, R. J.; Casey, A. W.; Clark, G. S., Jr.; Huckel, R. W.; Kindley, L. M.; Russell, J. P. J. Org. Chem. 1963, 28, 1740.
6. Tedeschi, R. J. J. Org. Chem. 1965, 30, 3045. For a more extensive discussion of the ethynylation of carbonyl compounds, see: Brandsma, L. Preparative Acetylenic Chemistry, 2nd ed.; Elsevier: Amsterdam, 1988; pp 79-96.
7. Tedeschi, R. J. J. Org. Chem. 1965, 30, 3045. For a more extensive discussion of the ethynylation of carbonyl compounds, see: Brandsma, L. Preparative Acetylenic Chemistry, 2nd ed.; Elsevier: Amsterdam, 1988; pp 79-96.
8. Bordwell, F G. Acc. Chem. Res. 1988, 21, 456.
9. Only in reactions involving a methyl ketone was a competitive aldol condensation an observable side reaction. Even then, the latter could be prevented by slow addition of the methyl ketone to the DMSO solution containing the terminal alkyne and alkoxide catalyst. Attempts to utilize an enolizable aldehyde (e.g., propionaldehyde and isobutyraldehyde) in this process, however, led to a complex mixture of products.
10. Use of other aprotic solvents in lieu of DMSO is feasible, although the rate at which alkynylation occurs decreases in less polar solvents. For example, use of tetrahydrofuran as the solvent in lieu of DMSO afforded alkynol 3a in approximately 50% yield after a reaction time of 20 h at room temperature. The rest of the product mixture consisted of unreacted starting materials. A similar experiment using benzene as the solvent afforded alkynol 3a in 35% yield after a reaction time of 20 h.
11. 3 in DMSO at room temperature. Since the latter allenyl alcohol was the major component in the reaction mixture after 2 h, its formation appears to be reversible. In none of the systems examined was the tertiary alkynol 3 contaminated with any allenic impurities