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Synlett 2003(6): 0870-0872
DOI: 10.1055/s-2003-38751
LETTER
© Georg Thieme Verlag Stuttgart ˙ New York

Zinc-Mediated Synthesis of α-C-Glycosides from 1,2-Anhydroglycosides

Song Xue*, Kai-Zhen Han, Lin He, Qing-Xiang Guo
Department of Chemistry, University of Science and Technology of China, Hefei, 230026, P.R.China
e-Mail: xuesong@ustc.edu.cn;
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Publikationsverlauf

Received 24 February 2003
Publikationsdatum:
17. April 2003 (online)

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Abstract

α-C-Glycosides have been prepared by the addition of organozinc reagents to glycal epoxides. Dialkyl and diaryl zinc reagents in the presence of CF3COOH provide the corresponding α-glycosides in 53-82% yields. Organozinc chlorides RZnCl formed by the reaction RLi with zinc chloride can also be successfully applied to this coupling reaction with high α-selectivity.

Key words

α-C-glycosides - epoxide - organozinc reagents - stereoselectivity - trifluoroacetic acid

    References

  • 1a Levy DE. Tang C. The Chemistry of C-Glycosides   Elsevier Science; Tarrytown New York: 1995. 
    Google Scholar
  • 1b Postema MHD. C-Glycoside Synthesis   CRC Press; Boca Raton: 1995. 
    Google Scholar
  • For recent review of C-glycosides see:
  • 2a Postema MHD. In Glycochemistry Principles, Synthesis and Applications   Bertozzi C. Wang PG. Marcel Dekker; New York: 2000.  p.77-131  
    CrossrefGoogle Scholar
  • 2b Du Y. Lindhart RJ. Vlahov IR. Tetrahedron  1998,  54:  9913 
    CrossrefGoogle Scholar
  • 3a Klein LL. McWhorter WW. Ko KP. Kishi Y. Uemura D. Hirata Y. J. Am. Chem. Soc.  1982,  104:  7362 
    CrossrefGoogle Scholar
  • 3b Best WM. Ferro V. Harle J. Stick RV. Tilbrook DMG. Aust. J. Chem.  1997,  50:  463 
    CrossrefGoogle Scholar
  • 3c Rainier JD. Allwein SP. J. Org. Chem.  1998,  63:  5310 
    CrossrefGoogle Scholar
  • 3d Rainier JD. Allwein SP. Tetrahedron Lett.  1998,  39:  9601 
    CrossrefGoogle Scholar
  • 3e Allwein SP. Cox JM. Howard BE. Johnson HWB. Rainier JD. Tetrahedron  2002,  58:  1997 
    CrossrefGoogle Scholar
  • 4a Bellosta V. Czernecki S. J. Chem. Soc., Chem. Commun.  1989,  199 
    CrossrefGoogle Scholar
  • 4b Evans DA. Trotter BW. Cote B. Tetrahedron Lett.  1998,  39:  1709 
    CrossrefGoogle Scholar
  • 5 Evans DA. Trotter BW. Coleman PJ. Cote B. Dias LC. Rajapakse HA. Tyler AN. Tetrahedron  1999,  55:  8671 
    CrossrefGoogle Scholar
  • 6a Bailey JM. Craig D. Gallagher PT. Synlett  1999,  132 
    Google Scholar
  • 6b Rainier JD. Cox JM. Org. Lett.  2000,  2:  2707 
    Google Scholar
  • 7 Parrish JD. Little RD. Org. Lett.  2002,  4:  1439 
    CrossrefGoogle Scholar
  • 8 Xue S. Li YL. Han KZ. Yin W. Wang M. Guo QX. Org. Lett.  2002,  4:  905 
    CrossrefGoogle Scholar
  • 9 Halcomb RL. Danishefsky SJ. J Am. Chem. Soc.  1989,  111:  6661 
    CrossrefGoogle Scholar
  • 11a

    The stereochemistry of α-C-glycosides was assigned from the coupling constants, which J 1,2 value ranged from 4.2 to 5.9 Hz.
    Crossref
  • 11b Leeuwenburgh MA. Timmers CM. van der Marel GA. van Boom JH. Mallet JM. Sinay PG. Tetrahedron Lett.  1997,  38:  6251 
    CrossrefGoogle Scholar
  • 11c

    See ref. [6b]

    Crossref
  • For trifluoracetic acid accelerated the cyclopropanation of olefins, see:
  • 12a Yang Z. Lorenz JC. Shi Y. Tetrahedron Lett.  1998,  39:  8621 
    Google Scholar
  • 12b Charette AB. Lacasse MC. Org. Lett.  2002,  4:  3351 
    Google Scholar
  • 13 For ZnCl2 mediated sodium malonate addition to glycal epoxides with β-selectivity, see: Timmers CM. Dekker M. Buijsman RC. van der Marel GA. Ethell B. Anderson G. Burchell B. Mulder GJ. van Boom JH. Bioorg. Med. Chem. Lett.  1997,  7:  1501 
    CrossrefGoogle Scholar
10

General Procedure for Preparation of α- C -Glycosides. To a solution of tri-O-benzyl-d-glucal (42 mg, 0.1 mmol) and 1.5 mL of CH2Cl2 at 0 °C was added a solution of dimethyldioxirane (0.15 mmol) in actone dropwise. After stirring for 30 min, the reaction mixture was concentrated in vacuum. The resulting white solid was taken up in CH2Cl2 (1.0 mL). To another solution of ZnR2 (0.2 mmol, 2 equiv) in 1 mL of CH2Cl2 at 0 °C was added CF3COOH (15 µL, 0.2 mmol, 2 equiv) very slowly via syringe under N2. After stirring for 30 min, to this solution was added the solution of epoxide dropwise via syringe. The mixture was stirred for 3-5 h from 0 °C to r.t. The reaction was quenched with sat. aq NH4Cl and extracted with CH2Cl2 (3 ¥ 10 mL). The combined organic solution was washed with brine, dried (MgSO4), and concentrated. Then, the product was isolated by silica gel column chromatography. Acetylated 3a: Mp 55-56 °C. 1H NMR (400 MHz, CDCl3): δ = 7.33-7.27 (m, 13 H), 7.16 (m, 2 H), 5.05 (dd, J = 8.8, 5.5 Hz, 1 H), 4.77 (d, J = 11.5 Hz, 1 H), 4.74 (d, J = 9.5 Hz, 1 H), 4.71 (d, J = 11.2 Hz, 1 H), 4.63 (d, J = 12.2 Hz, 1 H), 4.52 (d, J = 10.3 Hz, 1 H), 4.50 (d, J = 10.9 Hz, 1 H), 4.02 (m, 1 H), 3.82 (m, 1 H), 3.71-3.65 (m, 4 H), 1.99 (s, 3 H), 1.70 (m, 1 H), 1.48 (m, 1 H), 0.94 (t, J = 7.4 Hz, 3 H). 13C NMR (400 MHz, CDCl3): δ = 170.1, 138.4, 138.2, 138.0, 128.4, 128.3, 128.0, 127.8, 127.7, 127.6, 80.2, 77.7, 74.7, 74.6, 73.7, 73.5, 73.1, 71.6, 69.0, 20.9, 19.1, 9.6. HRMS (FAB+) calcd for C31H36O6: 505.2590 [MH+]. Found: 505.2585. Acetylated 3e: Mp 62-63 °C. 1H NMR (400 MHz, CDCl3): δ = 7.33-7.26 (m, 13 H), 7.15 (m, 2 H), 5.05 (dd, J = 8.6, 5.3 Hz, 1 H), 4.76 (d, J = 11.5 Hz, 1 H), 4.74 (d, J = 10.4 Hz, 1 H), 4.71 (d, J = 9.8 Hz, 1 H), 4.61 (d, J = 12.1 Hz, 1 H), 4.52 (d, J = 12.0 Hz, 1 H), 4.49 (d, J = 10.8 Hz, 1 H), 4.11 (m, 1 H), 3.82 (m, 1 H), 3.72-3.65 (m, 4 H), 3.51 (t, J = 6.6 Hz, 2 H), 1.99 (s, 3 H), 1.80-1.77 (m, 3 H), 1.55 (m, 1 H), 1.43-1.40 (m, 2 H). 13C NMR (400 MHz, CDCl3): δ = 170.1, 138.4, 138.1, 137.9, 129.7, 128.4, 128.3, 127.9, 127.8, 127.7, 127.6, 80.0, 77.5, 74.7, 74.6, 73.5, 72.9, 71.9, 68.9, 44.8, 32.2, 25.4, 22.6, 20.9. HRMS (FAB+) calcd for C33H39O6Cl: 567.2513 [MH+]. Found: 567.2500. Acetylated 3f: Mp 77-78 °C. 1H NMR (400 MHz, CDCl3): δ = 7.27-7.10 (m, 13 H), 7.10 (m, 2 H), 4.98 (dd, J = 8.7, 5.4 Hz, 1 H), 4.71 (d, J = 11.8 Hz, 1 H), 4.67 (d, J = 10.7 Hz, 1 H), 4.65 (d, J = 11.1 Hz, 1 H), 4.55 (d, J = 12.1 Hz, 1 H), 4.46 (d, J = 11.9 Hz, 1 H), 4.44 (d, J = 10.9 Hz, 1 H), 4.09-3.94 (m, 3 H), 3.74 (m, 1 H), 3.66-3.59 (m, 4 H), 1.96 (s, 3 H), 1.93 (s, 3 H), 1.71-1.51 (m, 4 H), 1.47-1.26 (m, 2 H). 13C NMR (400 MHz, CDCl3): δ = 171.2, 170.1, 138.4, 138.2, 138.1, 128.5, 128.4, 128.1, 127.9, 127.8, 127.7, 127.6, 80.1, 77.6, 74.8, 74.7, 73.6, 73.1, 72.1, 72.0, 69.0, 64.3, 29.8, 28.4, 25.7, 21.8, 21.0. HRMS (FAB+) calcd for C35H42O8: 591.2958 [MH+]. Found: 591.2952. Acetylated 3h: Mp 70-71 °C. 1H NMR (300 MHz, CDCl3): δ = 7.38 (m, 2 H), 7.29-7.19 (m, 16 H), 7.08 (m, 2 H), 5.13 (d, J = 5.7 Hz, 1 H), 4.91 (dd, J = 9.9, 5.7 Hz, 1 H), 4.81-4.71 (m, 3 H), 4.58 (d, J = 12.0 Hz, 1 H), 4.48 (d, J = 10.8 Hz, 1 H), 4.46 (d, J = 12.3 Hz, 1 H), 3.98 (m, 2 H), 3.71-3.63 (m, 3 H), 1.96 (s, 3 H). 13C NMR (300 MHz, CDCl3): δ = 170.2, 138.7, 138.2, 138.1, 132.1, 128.6, 128.5, 128.2, 128.1, 127.9, 127.8, 122.3, 89.6, 83.2, 81.4, 77.9, 75.5, 75.4, 74.2, 73.7, 72.8, 68.8, 66.3, 21.1. IR (KBr): ν = 2909, 2228, 1741, 1454, 1238, 1099, 1041 cm-1. HRMS (FAB+) calcd for C37H36O6: 599.2409 [MNa+]. Found: 599.2408.

14

For ZnCl2 mediated acetylide anion additions to glycal epoxides with α-selectivity, see ref. [11a]

15

For comparison, the reaction of n-butylmagnesium chloride with epoxide 2 in THF from -78 °C to 0 °C gave a 45:55 mixture of α- and β-C-glycoside.