Self-promoted aldol reaction between aldehyde having lewis base moiety and trimethylsilyl enolate

Chemistry Letters

Volumn 33, Issue 2, 2004, Pages 92-93

  Nakagawa, Takashi ^a,b   Fujisawa, Hidehiko ^a,b   Mukaiyama, Teruaki ^a,b  

^a KITASATO INSTITUTE   (Japan)

^b KITASATO UNIVERSITY   (Japan)

Author keywords

[No Author keywords available]

Indexed keywords

ALDEHYDE; TRIMETHYLSILYL DERIVATIVE;

ALDOL REACTION; ARTICLE; CHEMICAL ANALYSIS; CHEMICAL STRUCTURE; REACTION ANALYSIS; STRUCTURE ANALYSIS;

EID: 1942519767     PISSN: 03667022     EISSN: None     Source Type: Journal    
DOI: 10.1246/cl.2004.92     Document Type: Article

References (10)

1. a) H. Fujisawa and T. Mukaiyama, Chem. Lett., 2002, 18 2.
2. b) H. Fujisawa and T. Mukaiyama, Chem. Lett., 2002, 858.
3. c) T. Mukaiyama, H. Fujisawa, and T. Nakagawa, Helv. Chim. Acta, 85, 4518 (2002).
4. d) T. Nakagawa, H. Fujisawa, and T. Mukaiyama, Chem. Lett., 32, 462 (2003).
5. T. Nakagawa, H. Fujisawa, and T. Mukaiyama, Chem. Lett., 32, 696 (2003).
6. Lithium salt was prepared from carboxylic acid (0.4 mmol) and lithium ethoxide (freshly prepared from dry EtOH and n-BuLi) (0.36 mmol) in THF. After solvent was removed under reduced pressure, the residue was used without further purification.
7. In the case of aldol reaction between silyl enolate 1 and benzaldehyde in DMF at -19°C for 1 h, 1 was activated by DMF and the corresponding aldol was obtained in 43% yield without adding any catalyst (See Ref. 1a). The result of present reaction clearly indicates that 1 was activated effectively by 2a in DMF at -20°C.
8. Tetrabutylammonium salt was prepared by treating carboxylic acid (0.4 mmol) with methanol solution of tetrabutylammonium hydroxide (0.36 mmol) in THF. After solvent was removed under reduced pressure, the residue was azeotroped with toluene (1.0 mL, twice) and was used without further purification.
9. 2O. Organic layer was washed with brine and dried over anhydrous sodium sulfate. After filtration and evaporation of the solvent, the crude product was purified by preparative TLC to give the corresponding aldol (134.8 mg, 93%) as a white powder.
10. A. Tanaka, T. Terasawa, H. Hagihara, Y. Sakuma, N. Ishibe, M. Sawada, H. Takasugi, and H. Tanaka, Bioorg. Med. Chem., 6, 15 (1998).