Development of a method for the preparation of α-azido-masked acyl cyanides, synthetic equivalents of N-protected-C-activated α-amino acids

Tetrahedron

Volumn 56, Issue 11, 2000, Pages 1463-1468

  Nemoto, Hisao ^a   Ma, Rujian ^a   Ibaragi, Touru ^a   Suzuki, Ichiro ^a   Shibuya, Masayuki ^a  

^a UNIVERSITY OF TOKUSHIMA   (Japan)

Author keywords

Acyl anion; Amino acids and peptides; Azides; Cyanides; Threonine

Indexed keywords

ALPHA AMINO ACID; AZIDE; CYANIDE;

ARTICLE; CHEMICAL BINDING; CHEMICAL INTERACTION; CHEMICAL MODIFICATION; CHEMICAL REACTION; CONFORMATIONAL TRANSITION; PRIORITY JOURNAL; REACTION ANALYSIS; SYNTHESIS;

EID: 0034629433     PISSN: 00404020     EISSN: None     Source Type: Journal    
DOI: 10.1016/S0040-4020(00)00040-5     Document Type: Article

References (16)

1. (a) Nemoto, H.; Kubota, Y.; Yamamoto, Y. J. Org. Chem. 1990, 55, 4515-4516.
2. (b) Yamamoto, Y.; Kubota, Y.; Honda, Y.; Fukui, H.; Asao, N.; Nemoto, H. J. Am. Chem. Soc. 1994, 116, 3161-3162.
3. (c) Nemoto, H.; Kubota, Y.; Sasaki, N.; Yamamoto, Y. Synlett 1993, 465-466.
4. (d) Nemoto, H. J. Syn. Org. Chem., Jpn. 1994, 52, 1044-1052.
5. 2O]-R'. Nemoto, H.; Ibaragi, T.; Kido, M.; Bando, M.; Shibuya, M. Tetrahedron Lett. 1999, 40, 1319-1322.
6. (a) Stork, G.; Takahashi, T.; Kawamoto, I.; Suzuki, T. J. Am. Chem. Soc. 1978, 100, 8272-8273.; β,γ-unsaturated ketone:
7. (b) Takahashi, T.; Nemoto, H.; Kanda, Y.; Tsuji, J.; Fukazawa, Y.; Okajima, T.; Fujise, Y. Tetrahedron 1987, 43, 5499-5520.
8. 2
9. By using the MAC reagent 1B (R′=1-ethoxyethyl) instead of 1A, 6a was also converted to the desired adduct in high yield. However, the adduct cannot be used in further steps since the corresponding sulfonates were not obtained in reproducible yields. NMR analysis of the crude product indicated that the 1-ethoxyethyl moiety of the adduct was lost. Thus we focused on using 1A for further optimization.
10. 2. Nemoto, H.; Kubota, Y.; Yamamoto, Y. J. Chem. Soc., Chem. Commun. 1994, 1665-1666.
11. Ionic carbon-carbon bond formation between malononitrile and benzaldehyde has been reported without the use of any additive. Corson, B. B.; Stoughton, R. W. J. Am. Chem. Soc. 1928, 50, 2825-2837.
12. 2O gave the best results.
13. The fact that the reverse reaction occurs is supported by the kinetics of the hydrolysis of benzylidenemalononitrile. Bernasconi, C. F.; Howard, K. A.; Kanavarioti, A. J. Am. Chem. Soc. 1984, 106, 6827-6835.
14. tBu prevents the reverse reaction. Therefore, all the aldehyde 6h was consumed and a product was isolated after a short period. This result will be published after further optimization.
15. Massad S.K., Hawkins L.D., Baker D.J. J. Org. Chem. 48:1983;5180-5182.
16. Vaultier M., Knouzi N., Carrie R. Tetrahedron Lett. 24:1983;763-764.