Synthesis of 1- C-alkyl-α- d-glucopyranosides by Lewis acid- or Brønsted acid-catalyzed O-glycosidation

• Published in: Tetrahedron Vol. 62; no. 44; pp. 10383 - 10392
• Main Authors: Yamanoi, Takashi, Oda, Yoshiki, Matsuda, Sho, Yamazaki, Ippo, Matsumura, Kazuhide, Katsuraya, Kaname, Watanabe, Mikio, Inazu, Toshiyuki
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 29-10-2006
• Subjects: 1- C-Alkyl-glycopyranose; Brønsted acid; Glycosidation; Ketopyranoside; Lewis acid; Lewis acid; Brønsted acid; 1- C-Alkyl-glycopyranose; Ketopyranoside; Glycosidation
• ISSN: 0040-4020; 1464-5416
• DOI: 10.1016/j.tet.2006.08.059

We prepared several kinds of 1-
C-alkyl-2,3,4,6-tetra-
O-benzyl-α-
d-glucopyranose derivatives containing methyl, ethyl,
n-butyl, and benzyl groups as the alkyl groups at their anomeric positions. The Lewis acid- or Brønsted acid-catalyzed O-glycosidations using them as the glycosyl donors to synthesize 1-
C-alkyl-
d-glucopyranosides were investigated. Using 10
mol
% of triphenylmethyl perchlorate efficiently catalyzed the glycosidation of 2,3,4,6-tetra-
O-benzyl-1-
C-methyl-α-
d-glucopyranosyl dimethylphosphinothioate. The glycosidation using the 1-
C-alkyl-2,3,4,6-tetra-
O-benzyl-α-
d-glucopyranosyl acetates smoothly proceeded in the presence of only 5
mol
% of scandium(III) trifluoromethanesulfonate. The dehydration–condensation type glycosidation using the 1-
C-alkyl-2,3,4,6-tetra-
O-benzyl-α-
d-glucopyranoses was significantly promoted using 5
mol
% of bis(trifluoromethane)sulfonimide. These glycosidations successfully afforded various 1-
C-alkyl-α-
d-glucopyranosides in good yields with high α-stereoselectivities.
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