Solvent effect observed in nucleophilic substitution of 4′-(benzoyloxy)cordycepin with AlMe3: Stereochemical evidence for SNi mechanism

Journal of Organic Chemistry

Volumn 74, Issue 9, 2009, Pages 3402-3405

  Kubota, Yutaka ^a   Kunikata, Mayumi ^a   Haraguchi, Kazuhiro ^a   Tanaka, Hiromichi ^a  

^a SHOWA UNIVERSITY   (Japan)

Author keywords

[No Author keywords available]

Indexed keywords

CORDYCEPIN; DEOXYADENOSINE; DIASTEREOMERIC EXCESS; NUCLEOPHILIC SUBSTITUTIONS; SOLVENT EFFECTS;

STEREOSELECTIVITY;

4' (BENZOYLOXY)CORDYCEPIN; ALUMINUM DERIVATIVE; CORDYCEPIN DERIVATIVE; SOLVENT; UNCLASSIFIED DRUG;

ARTICLE; CONTROLLED STUDY; ISOMER; SOLVENT EFFECT; STEREOCHEMISTRY; SUBSTITUTION REACTION;

ALUMINUM COMPOUNDS; DEOXYADENOSINES; SOLVENTS; STEREOISOMERISM;

EID: 66449100912     PISSN: 00223263     EISSN: None     Source Type: Journal    
DOI: 10.1021/jo900289h     Document Type: Article

References (14)

1. Itoh, Y.; Haraguchi, K.; Tanaka, H.; Gen, E.; Miyasaka, T. J. Org. Chem. 1995, 60, 656-662.
2. Haraguchi, K.; Sumino, M.; Tanaka, H. J. Org. Chem. 2006, 71, 4433-4438.
3. Kubota, Y.; Kunikata, M.; Ishizaki, N.; Haraguchi, K.; Odanaka, Y.; Tanaka, H. Tetrahedron 2008, 64, 2391-2396.
4. For NOE data of 8a and 8b, see ref 3.
5. The values of dipole moment and dielectric constant in Table 1 were taken from: Lange's Handbook of Chemistry, 15th ed.; Dean, J. H., Ed.; McGraw-Hill: New York, 1999.
6. The NOEs of 9a and 9b were measured in CDCl3. For 9a: H-5′b/H-8 (0.9%), 4′-Me/H-1′(3.7%); for 9b: H-8/4′-Me (1.2%), H-1′/H-5′b (0.6%). Of the two protons at the 5′-position, the one that appears at a higher field is designated as H-5′a and the other as H-5′b.
7. Kubota, Y.; Haraguchi, K.; Kunikata, M.; Hayashi, M.; Ohkawa, M.; Tanaka, H. J. Org. Chem. 2006, 71, 1099-1103.
8. The reactions corresponding to entries 2 and 3 were also carried out by using 3′,5′-bis-O-triethylsilyl- and 3′,5′-bis- O-(tert-butyldiphenylsilyl)-protected substrates. However, no significant difference was seen in terms of diastereo-selectivity.
9. This "early quenching" experiment was also carried out for the reactions in entries 2, 4, 5, 8, and 9. As a result, it was confirmed that the substrate (8a or 8b) recovered from these experiments did not contain the respective 4′-epimer as evidenced by 1H NMR analysis.
10. Kennedy, J. P.; Desai, N. V.; Sivaram, S. J. Am. Chem. Soc. 1973, 95, 6386-6390.
11. Miller, D. B. J. Org. Chem. 1966, 31, 908-912.
12. Kennedy, J. P. J. Org. Chem. 1970, 35, 532-536.
13. Hashimoto, S.; Kitagawa, Y.; Iemura, S.; Yamamoto, H.; Nozaki, H. Tetrahedron Lett. 1976, 2615-1616.
14. Itoh, A.; Oshima, K.; Sasaki, S.; Yamamoto, H.; Hiyama, T.; Nozaki, H. Tetrahedron Lett. 1979, 4751-4754.