Template-directed intramolecular C-glycosidation. Stereoselective synthesis of monocyclic C-glycosides

Tetrahedron Letters

Volumn 39, Issue 45, 1998, Pages 8325-8328

  Craig, Donald ^a   Payne, Andrew H ^a   Warner, Peter ^b  

^a IMPERIAL COLLEGE LONDON   (United Kingdom)

^b ASTRAZENECA   (United Kingdom)

Author keywords

[No Author keywords available]

Indexed keywords

DECALIN; GLYCOSIDE; SILANE DERIVATIVE; TETRAHYDROPYRAN DERIVATIVE;

ARTICLE; CYCLIZATION; GLYCOSYLATION; MOLECULAR DYNAMICS; OXIDATION; SYNTHESIS;

EID: 0032487801     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/S0040-4039(98)01826-7     Document Type: Article

References (21)

1. 1. Levy, D. E.; Tang, C. The Chemistry of C-Glycosides, Pergamon: Oxford, 1995.
2. 2. Martin and co-workers have reported extensively on intramolecular C-arylation and related processes using cation-mediated transformations. See: Martin, O. R.; Hendricks, C. A. V.; Deshpande, P. P.; Cutler, A. B.; Kane, S. A.; Rao, S. P. Carbohydr. Res. 1990, 196, 1-58 and references therein.
3. 3. Craig, D.; Munasinghe, V. R. N. Tetrahedron Lett. 1992, 33, 663-666.
4. 13C nmr and ir spectra, and which showed low-resolution ms and either elemental combustion analysis or high-resolution ms characteristics in accord with the assigned structures.
5. 5. Stewart, A. O.; Williams, R. M. J. Am. Chem. Soc. 1985, 107, 4289-4296.
6. 6. Duboudin, J. G.; Jousseaume, B. J. Organometal. Chem. 1979, 168, 1-11.
7. N2 reaction of 6 with the conjugate base of 2-mercaptopyridine.
8. 8. Compounds 7, 8 and 3 typically were obtained as ca. 8:1 mixtures of anti:syn thioglycoside anomers.
9. 1H nmr n.O.e. studies; we thank Mr Dick Sheppard and Mr Paul Hammerton of this Department for these experiments.
10. 10. Silyl enol etherification of the more sterically hindered ketones 8b and 8c gave small (=5%) amounts of the alternative regioisomers.
11. 11. Chopard, P. A.; Hudson, R. F. J. Org. Chem. 1963, 28, 2446-2447.
12. 12. Heathcock, C. H.; Hecker, S. J. J. Org. Chem. 1985, 50, 5159-5166.
13. 13. We speculate that the nitrogen and/or sulfur atom of the PyS group acts as a catalyst poison.
14. 14. This ratio of ketones 9c and 10c was obtained when cyclisation of 3c was carried out at -20°C.
15. 15. This ratio of ketones 9b and 10b was obtained when cyclisation of 3b was carried out at 25°C.
16. 2 in organic synthesis, see Kagan, H. B.; Namy, J. Tetrahedron 1986, 42, 6584-6614.
17. 3).
18. 3).
19. 19. The second most abundant product (20%) was the corresponding enol ether derived from 10c. The minor product (10%) was the isomeric tetrasubstituted silyl enol ether. The total yield was 80%.
20. 2).
21. 21. ZENECA in the U.K. is part of ZENECA Limited.