Acylation of a transient Ti(IV)-enolate by acyl halides and anhydrides. Facile synthesis of α-hydroxy-β-ketoesters

Tetrahedron

Volumn 52, Issue 33, 1996, Pages 11037-11044

  Clerici, Angelo ^a   Clerici, Laura ^a   Porta, Ombretta ^a  

^a POLITECNICO DI MILANO   (Italy)

Author keywords

[No Author keywords available]

Indexed keywords

ESTER DERIVATIVE; HYDROXYACID; OXOACID;

ARTICLE; CATALYSIS; DRUG SYNTHESIS; PRIORITY JOURNAL; REACTION ANALYSIS; STEREOCHEMISTRY;

EID: 0030581391     PISSN: 00404020     EISSN: None     Source Type: Journal    
DOI: 10.1016/0040-4020(96)00621-7     Document Type: Article

References (21)

1. 1. Yamada, Y.; Iguchi, K.; Hosaka, K.; Hagiwara, K. Synthesis 1974, 669.
2. (b) Hori, T.; Nakanishi, K. J. Chem. Soc. Chem. Comm. 1969, 528.
3. 2. March, J. Advanced Organic Chemistry, 3rd ed., J. Wiley and Sons: New York, 1985; p 850 and references cited herein.
4. 3. (a) Morrison, J. D.; Mosher, H. S. Asymmetric Organic Reactions, Prentice Hall: New Jersey, 1971, pp 50-83.
5. (b) Tatibouet, F.; Fréon, P. Bull. Soc. Chim. French Ed. 1963, 1496.
6. 4. Mikami, K.; Shimizu, S. Chem. Rev. 1992, 1021.
7. 5. Clerici, A.; Clerici, L.; Porta, O. J. Org. Chem. 1995, 60, 480.
8. 6. Clerici, A.; Clerici, L.; Malpezzi, L.; Porta, O. Tetrahedron 1995, 51, 13385.
9. 7. Clerici, A.; Clerici, L.; Porta, O. Tetrahedron Lett. 1995, 36, 5955.
10. 8. The few literature methods, available for the synthesis of 5, require multi-step and low-yielding reactions: (a) Le Dao, H.; Dayer, F.; Duc, L.; Rodè-Gowal, H.; Dahn, H. Helv. Chim. Acta 1974, 57, 2215.
11. (b) Beccalli, E. M.; Marchesini, A. Gazz. Chim. Ital. 1984, 114, 389.
12. 2 (2.1) are now commercially available from Aldrich.
13. 1H NMR (DMSO) spectrum evidences the presence of THF and pyridine in the ratio 1:4. It is very sensitive to moisture and is completely destroyed when the reaction is quenched with water.
14. 3 was over in less than 5 min and afforded dimer 2a (59% yield) as the almost exclusive product.
15. 12. In the absence of electrophiles, which drive B from the equilibrium, both B and 1 may regenerate A, the former by oxidative and the latter by reductive dimerization (see ref 5).
16. 13. Araneo, S.; Clerici, A.; Porta, O. Tetrahedron Lett. 1994, 35, 2213.
17. 14. (a) Fersht, A. R.; Jencks, W. P. J. Am. Chem. Soc. 1970, 92, 5432.
18. (b) Deady, L. W.; Finlayson, W. L. Aust. J. Chem. 1983, 36, 1951.
19. (c) March, J. Advanced Organic Chemistry, 3rd ed., J. Wiley and Sons: New York, 1985; p 333.
20. 4 complexes rather than the formation of a N-acyl pyridinium ion: Patay, S. The Chemistry of Acyl Halides chapt 4, p 131 and references cited herein.
21. 16. Reetz, M. T. Organotitanium Reagents in Organic Synthesis, Springer-Verlag: Berlin, 1986, chapts 1 and 5.