Control of α/β Stereoselectivity in Lewis Acid Promoted C‐Glycosidations Using a Controlling Anomeric Effect Based on the Conformational Restriction Strategy

Angewandte Chemie International EditionVolume 42, Issue 9 p. 1021-1023 Communication Control of α/β Stereoselectivity in Lewis Acid Promoted C-Glycosidations Using a Controlling Anomeric Effect Based on the Conformational Restriction Strategy† Satoru Tamura, Satoru Tamura Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo 060-0812, Japan, Fax: (+81) 11-706-4980Search for more papers by this authorHiroshi Abe Dr., Hiroshi Abe Dr. Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo 060-0812, Japan, Fax: (+81) 11-706-4980Search for more papers by this authorAkira Matsuda Prof., Akira Matsuda Prof. Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo 060-0812, Japan, Fax: (+81) 11-706-4980Search for more papers by this authorSatoshi Shuto Prof., Satoshi Shuto Prof. [email protected] Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo 060-0812, Japan, Fax: (+81) 11-706-4980Search for more papers by this author Satoru Tamura, Satoru Tamura Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo 060-0812, Japan, Fax: (+81) 11-706-4980Search for more papers by this authorHiroshi Abe Dr., Hiroshi Abe Dr. Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo 060-0812, Japan, Fax: (+81) 11-706-4980Search for more papers by this authorAkira Matsuda Prof., Akira Matsuda Prof. Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo 060-0812, Japan, Fax: (+81) 11-706-4980Search for more papers by this authorSatoshi Shuto Prof., Satoshi Shuto Prof. [email protected] Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo 060-0812, Japan, Fax: (+81) 11-706-4980Search for more papers by this author First published: 26 February 2003 https://doi.org/10.1002/anie.200390261Citations: 58 † This work was supported by a Grant-in-Aid for Creative Scientific Research (13NP0401) and a Research Fellowship for Young Scientists (to H.A.) from the Japan Society for the Promotion of Science. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat Graphical Abstract The kinetic anomeric effect has been used to control both α and β stereoselectivity in glycosidation reactions. Depending on the restricted conformation 4C1 or 1C4 of the substrate, the anomeric α (1→2) or β product (3→4) was obtained highly stereoselectively from the Lewis acid promoted anomeric allylation with allyltrimethylsilane (TIPS=triisopropylsilyl). Supporting Information Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2003/z19925_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article. References 1 1aD. E. Leavy, C. Tang, The Chemistry of C-Glycosides, Pergamon, Oxford, 1995; Google Scholar 1bM. H. D. Postema, C-Glycoside Synthesis, CRC, Boca Raton, 1995; Google Scholar 1cY. Du, R. J. Linhardt, Tetrahedron 1998, 54, 9913–9959. 10.1016/S0040-4020(98)00405-0 CASWeb of Science®Google Scholar 2For examples, see: Google Scholar 2aM. D. Lewis, J. K. Cha, Y. Kishi, J. Am. Chem. Soc. 1982, 104, 4976–4978; 10.1021/ja00382a053 CASWeb of Science®Google Scholar 2bA. Hosomi, Y. Sakata, H. 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Matsuda, Tetrahedron Lett. 2001, 42, 6159–6161. 10.1016/S0040-4039(01)01233-3 CASWeb of Science®Google Scholar 18In hexopyranoses, the steric effect of the 5-hydroxymethyl moiety would significantly affect the course of their glycosidation reactions, especially in the case of β-axial attack at the 1C4-restricted substrate because of 1,5-diaxial repulsion, and this would disturb the exact estimation of the anomeric effect on the stereoselectivity. Thus, xylose derivatives that lack a carbon substituent at the 5-position were selected as model substrates. Google Scholar 19 19aT. Mukaiyama, Y. Murai, S. Shoda, Chem. Lett. 1981, 431–432; 10.1246/cl.1981.431 CASWeb of Science®Google Scholar 19bK. C. Nicolaou, R. E. Dolle, D. P. Panahatjis, J. L. Randall, J. Am. Chem. Soc. 1984, 106, 4189–4192. 10.1021/ja00327a021 CASWeb of Science®Google Scholar 20Typical 1H NMR coupling constants for the conformationally restricted substrates in CDCl3: 2 (α-anomer), J1,2=2.8, J2,3=9.4, J4,5b=9.7 Hz; 3, J1,2, J2,3, J3,4, J4,5b, J2,3≈0 Hz. The 1C4-restricted 1-β-fluoro structure of 3 was also confirmed by 19F NMR spectroscopy in CDCl3: JF,1=49.9, JF,2=5.1 Hz (conformational analysis of pyranoses by 19F NMR: M. Michalik, M. Hein, M. Frank, Carbohydr. Res. 2000, 327, 185–218). 10.1016/S0008-6215(99)00323-7 CASPubMedWeb of Science®Google Scholar 21For experimental details, see Supporting Information. Google Scholar 22The 1H NMR spectral data of the tri-O-benzoates 9 and 10 were in accord with those of authentic samples synthesized previously by another method.[9] Google Scholar 23The α/β ratio was determined based on the anomeric proton signals in the 1H NMR spectrum. Google Scholar 24It may be possible that the β-product 7 was produced in part through the SN2 reaction of the α anomer of the donor 2. Google Scholar Citing Literature Volume42, Issue9March 3, 2003Pages 1021-1023 ReferencesRelatedInformation