Synthesis of several novel optically active nitroxyl radicals

Tetrahedron Letters

Volumn 37, Issue 44, 1996, Pages 7933-7936

  Braslau, Rebecca ^a   Kuhn, Heiko ^a   Burrill II, Leland C ^a   Lanham, Kenneth ^a   Stenland, Chris J ^a  

^a UNIVERSITY OF CALIFORNIA   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

NITROXIDE DERIVATIVE; RADICAL;

ARTICLE; DRUG PURIFICATION; DRUG SYNTHESIS; ELECTRON SPIN RESONANCE; ENANTIOMER; TECHNIQUE;

EID: 0030605141     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/0040-4039(96)01800-X     Document Type: Article

References (21)

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2. 2. a. Rychnovsky, S. D.; McLernon, T. L; Rajapakse, H. J. Org. Chem. 1996, 61, 1194-1195.
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4. 3. General references: a. Volodarsky, L. B.; Reznikov, V. A.; Ovcharenko, V. I. Synthetic Chemistry of Stable Nitroxides, CRC Press, Boca Raton, 1994;
5. b. Aurich, H. G. in Nitrones, Nftronates and Nitroxides, ed. S. Patai and Z. Rappoport, Wiley, Chichester, 1989, chapters 4 and 5;
6. c. Volodarsky, L. B. Imidazoline Nitroxides, CRC Press, Boca Raton, 1988, vol. 1;
7. d. Keana, J. F. W. in Spin Labeling in Pharmacology, ed. J. L. Holtzman, Academic Press, Orlando, 1984, chapter 1;
8. e. Keana, J. F. W. Chem. Rev. 1978, 78, 37-64.
9. 4. Novel compounds 2, 4, 8 and 11 have been fully characterized, including satisfactory HRMS or elemental analysis.
10. 2O mixture and filtered through a 5-cm pipette-plug of neutral Alumina (Brockmann III) to give 11.2 mg of (-)-4 as a crystalline orange solid (26% yield).
11. n = 15.0, 15.0, 13.7, 14.1 and 13.9 G respectively.
12. 7. Banks, M. R.; Cadogan, J. I. G.; Gosney, I.; Grant, K. J.; Hodgson, P. K. G.; Thorburn, P. Heterocycles 1994, 37, 199-206. Note: triphosgene was used in place of phosgene.
13. 8. Bartlett, P. D.; Knox, L. H. Org. Synth. Coll. Vol. V, 1973, 689-691. Note: ketopinic acid is now available from Aldrich.
14. 9. Van, T.-H.; Chu, V.-V.; Lin, T.-C.; Wu, C.-H.; Liu, L.-H. Tetrahedron Lett. 1991, 32, 4959-4962.
15. 10. The amino ketone gave a negative Beilstein's test for the presence of the hydrochloride salt, however the melting point (197 °C) was identical to that of the salt reported by Beak: Beak, P.; Harris, B. R. J. Am. Chem. Soc. 1974, 96, 6363-6372.
16. 11. For a discussion of this reaction and leading references, see: reference 3a, pp. 35-36.
17. 12. Kornblum, N.; Clutter, R. J.; Jones, W. J. J. Am, Chem. Soc. 1956, 78, 4003-4004.
18. 13. a. Such low yields seem to be inherent to this method: Brière, R.; Rassat, A. Bull. Soc. Chim. Fr. 1965, 378-381;
19. b. Based on the work of Bartoli, G.; Marcantoni, E.; Petrini, M. J. Chem. Soc., Chem. Comm. 1993, 1373-1374, the use of cerium reagents on a similar substrate enhances the yields in this class of transformations (Wedeking, T., unpublished work from this lab).
20. 14. Compound 10 has been previously prepared: Yan, T.-H.; Tan, C.-W.;Lee, H.-C.; Lo, H.-C.; Huang, T.-Y. J. Am. Chem. Soc. 1993, 115, 2613-2621.
21. 15. The yield was determined by integration of the ESR signal of 12 relative to ESR spectra of standardized solutions of 2,2,6,6-tetramethyl-1-piperidinyloxyl (TEMPO). The use of purified mCPBA (Fieser, L.F. and Fieser, M. Reagents for Organic Synthesis, Vol. 1, Wiley: New York, 1967; p. 135) should provide a much cleaner and higher yielding reaction.