Synlett 2006(15): 2379-2382  
DOI: 10.1055/s-2006-949649
LETTER
© Georg Thieme Verlag Stuttgart · New York

A Novel Synthetic Route to α-Galactosyl Ceramides and iGb3 Using DTBS-Directed α-Selective Galactosylation

Akiyoshi Kimuraa, Akihiro Imamura*a,b, Hiromune Andoc, Hideharu Ishidaa,b, Makoto Kiso*a,b
a Department of Applied Bioorganic Chemistry, Faculty of Applied Biological Sciences, Gifu University, 1-1 Yanagido, Gifu-shi, Gifu 501-1193, Japan
b CREST, Japan Science and Technology Corporation (JST), 1-1 Yanagido, Gifu-shi, Gifu 501-1193, Japan
c Division of Instrumental Analysis, Life Science Research Center, Gifu University, 1-1 Yanagido, Gifu-shi, Gifu 501-1193, Japan
Fax: +81(58)2932918; e-Mail: imamu@cc.gifu-u.ac.jp; e-Mail: kiso@cc.gifu-u.ac.jp;
Further Information

Publication History

Received 27 June 2006
Publication Date:
08 September 2006 (online)

Abstract

A novel synthetic route to α-galactosyl ceramides and isoglobotrihexosylceramide (iGb3), which can activate NKT cells, was developed by exploiting a di-tert-butylsilylene-directed α-selective galactosylation procedure.

9

Compound 13: 1H NMR (500 MHz, CDCl3): δ = 0.87 (t, 6 H, 2 × CH3), 0.96 and 1.11 (2 s, 18 H, 2 t-Bu), 1.24 (m, 52 H, CH2), 1.65 (q, 2 H, NHCOCH2CH 2), 1.86 (m, 2 H, H-5 Cer , H-5′ Cer ), 2.20 (t, 2 H, NHCOCH 2CH2), 3.70 (dd, 1 H, H-1 Cer ), 3.79 (dd, 1 H, H-1′ Cer ), 3.95 (s, 1 H, H-5 Gal ), 4.25 (s, 2 H, H-6 Gal , H-6′ Gal ), 4.60 (m, 1 H, J 2,3 = 3.4 Hz, H-2 Cer ), 4.85 (d, 1 H, J 3,4 = 3.2 Hz, H-4 Gal ), 5.21 (d, 1 H, J 1,2 = 3.7 Hz, H-1 Gal ), 5.32 (m, 1 H, J 3,4 = 4.6 Hz, H-4 Cer ), 5.49 (dd, 1 H, J 2,3 = 10.7 Hz, J 3,4 = 3.2 Hz, H-3 Gal ), 5.55 (dd, 1 H, J 2,3 = 3.4 Hz, J 3,4 = 4.6 Hz, H-3 Cer ), 5.71 (dd, 1 H, J 1,2 = 3.7 Hz, J 2,3 = 10.7 Hz, H-2 Gal ), 6.38 (d, 1 H, NH), 7.61 (m, 20 H, 4 × Ph). 13C NMR (100 MHz, CDCl3): δ = 14.1, 20.7, 22.7, 23.3, 25.6, 25.7, 27.1, 27.2, 27.5, 28.8, 29.4, 29.5, 29.6, 29.6, 29.7, 29.7, 31.9, 36.9, 48.8, 66.9, 67.7, 68.5, 69.0, 70.8, 71.1, 72.9, 73.8, 98.5, 128.2, 128.3, 128.4, 128.6, 129.4, 129.5, 129.7, 129.7, 129.8, 130.0, 133.0, 133.3, 165.1, 166.0, 166.2, 166.3, 173.0. Compound 15: 1H NMR (500 MHz, CDCl3): δ = 0.88 (t, 6 H, 2 × CH3), 0.96 and 1.11 (2 s, 18 H, 2 × t-Bu), 1.24 (m, 50 H, CH2), 1.57 (t, 2 H, NHCOCH2CH 2), 1.98 (q, 2 H, H-6 Cer , H-6′ Cer ), 2.10 (m, 2 H, NHCOCH 2CH2), 3.70 (dd, 1 H, J gem = 10.7 Hz, J 1,2 = 4.6 Hz, H-1′ Cer ), 3.84 (dd, 1 H, J gem = 10.7 Hz, H-1 Cer ), 4.19 (dd, 1 H, J gem = 12.6 Hz, H-6′ Gal ), 3.92 (s, 1 H, H-5 Gal ), 4.28 (dd, 1 H, J gem = 12.6 Hz, H-6 Gal ), 4.50 (m, 1 H, J 1,2 = 4.6 Hz, H-2 Cer ), 4.88 (d, 1 H, H-4 Gal ), 5.28 (d, 1 H, J 1,2 = 3.7 Hz, H-1 Gal ), 5.49 (m, 2 H, H-3 Cer , H-4 Cer ), 5.56 (dd, 1 H, H-3 Gal ), 5.74 (m, 2 H, H-5 Cer , NH), 5.76 (dd, 1 H, J 1,2 = 3.7 Hz, H-2 Gal ), 7.66 (m, 15 H, 3 × Ph). 13C NMR (100 MHz, CDCl3): δ = 14.1, 20.7, 22.7, 23.3, 25.8, 27.2, 27.5, 28.9, 29.2, 29.3, 29.4, 29.4, 29.5, 29.5, 29.6, 29.6, 29.7, 29.7, 31.9, 32.3, 36.9, 51.2, 66.8, 67.4, 67.7, 68.5, 70.9, 71.1, 74.4, 97.9, 124.6, 128.2, 128.3, 128.3, 128.4, 129.0, 129.4, 129.6, 129.7, 129.7, 129.8, 129.9, 133.0, 133.1, 133.2, 137.5, 165.2, 166.0, 166.2, 172.7.