Full conversion in diastereoselective aldol additions using 'naked' enolates under catalytic amount of phosphazene base: The hydroxypinanone as chiral auxiliary

Synlett

Volumn , Issue 3, 2000, Pages 327-330

  Solladié Cavallo, Arlette ^a   Crescenzi, Benedetta ^a  

^a UNIVERSITÉ DE STRASBOURG   (France)

Author keywords

Catalytic aldolization; Phosphazene base; Threonine

Indexed keywords

ALCOHOL DERIVATIVE;

ARTICLE; CATALYSIS; CHIRALITY; DIASTEREOISOMER; REACTION ANALYSIS; STEREOSPECIFICITY; SYNTHESIS;

EID: 0343114378     PISSN: 09365214     EISSN: None     Source Type: Journal    
DOI: None     Document Type: Article

References (17)

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2. Solladié-Cavallo A., Koessler J.L., Fischer J., DeCian A. Gazz. Chim. Ital. 1996, 126, 173.
3. Solladié-Cavallo A., Nsenda T. Tetrahedron Lett. 1998, 39, 2191.
4. Enolates are said to be 'naked' when they are metal-free, the counter-cation being organic. Tight/loose aggregates formed with metallic-cations are replaced by intimate/solvent-separated ion pairs.
5. Solladié-Cavallo A., Roche D., Fischer J., DeCian A. J. Org. Chem. 1996, 61, 2690.
6. Schwesinger R. Nachr. Chem. Tech. Lab. 1990, 38, 1214.
7. Schwesinger R., Schlemper H. Angew. Chem, Int. Ed. 1987, 26, 1167.
8. + is less acidic than the iminoesters 2a(b) one can postulate that EtP2 is regenerated during the addition according to the following assisted process: (Formula Presented)
9. 2).
10. 2).
11. 3OH, 98/2).
12. 6/TMS) : Very similar but 1.40 (s, 9H) instead of the Et-signals. For H2 and H3 of the chain cf. Table 2.
13. As configurations of diastereomers II and III have not been assigned, the threolerythro selectivities calculated for the 83/ 3/0/14 mixture (Table 1) are 86/14 and 83/17. In the same way 82/3/0/15 leads to 85/15 and 82/18.
14. G. Bold, R.O. Duthaler, M. Riediker Angew. Chem. Int. Ed. Engl. 1989, 28, 497 and R.O. Duthaler, A. Hafner Chem. Rev. 1992, 92, 807 and included references.
15. G. Bold, R.O. Duthaler, M. Riediker Angew. Chem. Int. Ed. Engl. 1989, 28, 497 and R.O. Duthaler, A. Hafner Chem. Rev. 1992, 92, 807 and included references.
16. Solladié-Cavallo A., Koessler J.L., Isarno T., Roche D., Andriamiadanarivo R. Synlett 1997, 217.
17. Jastrbeski J.T., Van Koten G., Van De Mieroop W.F. Inorg. Chim. Acta 1988, 142, 169.