Preparation of α-C-Glycosides from Glycals

Organic Letters

Volumn 4, Issue 9, 2002, Pages 1439-1442

  Parrish, J D ^a   Daniel Little, R ^a  

^a UNIVERSITY OF CALIFORNIA   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

DRUG DERIVATIVE; DYES, REAGENTS, INDICATORS, MARKERS AND BUFFERS; GLUCONATE CALCIUM; GLYCOSIDE;

ARTICLE; CHEMISTRY; OXIDATION REDUCTION REACTION; SYNTHESIS;

CALCIUM GLUCONATE; GLYCOSIDES; INDICATORS AND REAGENTS; OXIDATION-REDUCTION;

EID: 0037007710     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol025575a     Document Type: Article

References (23)

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2. (b) Postema, M. H. D. C-Glycoside Synthesis; CRC Press: London, 1995.
3. For a review, see: Toto, H.; He, W.; Waki, Y.; Yokoyama, M. Synlett 1998, 700. Also see: Praly, J.-P. Adv. Carbohydr. Chem. Biochem. 2001, 56, 65.
4. For a review, see: Toto, H.; He, W.; Waki, Y.; Yokoyama, M. Synlett 1998, 700. Also see: Praly, J.-P. Adv. Carbohydr. Chem. Biochem. 2001, 56, 65.
5. Giese, B.; Dupuis, J.; Leising, M.; Nix, M.; Lindner, H. J. Carbohydr. Res. 1987, 171, 329.
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10. (c) Gansäuer, A. Synlett 1998, 801.
11. Danishefsky, S. J.; Halcomb, R. L. J. Am. Chem. Soc. 1989, 111, 6661.
12. This representation of 3 may be overly simplified, but it allows one to see the impact of anomeric stabilization leading to the observed products. For more on the conformations of these types of radicals, see refs 3 and 14.
13. For examples, see: (a) Evans, D. A.; Trotter, B. W.; Coleman, P. J.; Cote, B.; Dias, L. C.; Rajapakse, H. A.; Tyler, A. N. Tetrahedron 1999, 55, 8671.
14. (b) Rainier, J. D.; Allwein, S. P.; Cox, J. M. J. Org. Chem. 2001, 66, 1380. Rainier has published a report using boron- and aluminum- mediated alkylations to form α-C-glycosides: Rainier, J. D.; Cox, J. M. Org. Lett. 2000, 2, 2707.
15. (b) Rainier, J. D.; Allwein, S. P.; Cox, J. M. J. Org. Chem. 2001, 66, 1380. Rainier has published a report using boron- and aluminum-mediated alkylations to form α-C-glycosides: Rainier, J. D.; Cox, J. M. Org. Lett. 2000, 2, 2707.
16. In addition to deuterium trapping and NMR data, to our knowledge all examples of trapping reactions of anomeric radicals leads predominantly, if not exclusively, to α-configured products.
17. For reviews, see: Dondoni, A.; Marra, A. Chem Rev. 2000, 100, 4395.
18. (b) Taylor, C. M. Tetrahedron 1998, 54, 11317.
19. Ferreira, P. M. T.; Maia, H. L. S.; Monteiro, L. S.; Sacramento, J. J. Chem. Soc., Perkin Trans. 1 1999, 24, 3697.
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21. 2TiCl system appears to be less Lewis acidic. See ref 5b.
22. For a review on anomeric radicals, see: Descotes, G. J. Carbohydr. Chem. 1988, 7, 1. Also see ref 2.
23. 3 in acetonitrile reference electrode. This electrode has a potential of ca. 0.3 V versus SCE.