A highly selective synthesis of (Z)-α,β-unsaturated ketones

Tetrahedron Letters

Volumn 40, Issue 37, 1999, Pages 6725-6728

  Yu, Wensheng ^a   Su, Mei ^a   Jin, Zhendong ^a  

^a UNIVERSITY OF IOWA   (United States)

Author keywords

(Z) , unsaturated ketone; Wadsworth Emmons reaction

Indexed keywords

ALDEHYDE; KETONE; PHOSPHONIC ACID DERIVATIVE; REAGENT;

ARTICLE; CHEMICAL REACTION; CHEMICAL REACTION KINETICS; MOLECULAR INTERACTION; REACTION ANALYSIS; SYNTHESIS;

EID: 0033543729     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/S0040-4039(99)01393-3     Document Type: Article

References (10)

1. Taber, D. F.; Herr, R. J.; Pack, S. K.; Geremia, J. M. J. Org. Chem. 1996, 61, 2908 and references cited therein.
2. Still, W. C.; Gennari, C. Tetrahedron Lett. 1983, 24, 4405.
3. Hensel, M. J.; Fuchs, P. L. Synth. Commun. 1986, 16, 1285.
4. Patois, C.; Savignac, P.; About-Jaudet, E.; Collignon, N. Synth. Commun. 1991, 21, 2391.
5. 1H NMR of the crude reaction mixture showed there are many unidentified side-products along with the desired product 6.
6. Several other procedures have been examined to minimize the dialkylation product 8. It appeared the present conditions gave the highest yield of compound 7 and the best ratio as well. It is quite difficult to separate both compounds. Therefore, we simply used the mixture of compounds 7 and 8 and calculated the amount of aldehyde, base, and crown ether needed for the reaction according to the amount of 7 present in the mixture. The separation of the Wadsworth-Emmons reaction product and compound 8 is very easy.
7. All compounds were fully characterized.
8. Ireland, R. E.; Meissner, R. S. J. Org. Chem. 1991, 56, 4566.
9. 5 equiv. of 18-crown-6 was used by Still and Gennari, see Ref. 2.
10. (Z)-α,β-Unsaturated ketones, to the extent that they can be purified, are prone to isomerization.