Potential bile acid metabolites. 24. An efficient synthesis of carboxyl-linked glucosides and their chemical properties.
A facile and efficient synthesis of the carboxyl-linked glucosides of bile acids is described. Direct esterification of unprotected bile acids with 2,3,4,6-tetra-O-benzyl-D-glucopyranose in pyridine in the presence of 2-chloro-1,3,5-trinitrobenzene as a coupling agent afforded a mixture of the alpha- and beta-anomers (ca. 1:3) of the 1-O-acyl-D-glucoside benzyl ethers of bile acids, which was separated effectively on a C18 reversed-phase chromatography column (isolated yields of alpha- and beta-anomers are 4-9% and 12-19%, respectively). Subsequent hydrogenolysis of the alpha- and beta-acyl glucoside benzyl ethers on a 10% Pd-C catalyst in acetic acid/methanol/EtOAc (1:2:2, by vol) at 35 degrees C under atmospheric pressure gave the corresponding free esters in good yields (79-89%). Chemical specificities such as facile hydrolysis and transesterification of the acyl glucosides in various solvents were also discussed.
Lida
Takashi
T
Department of Chemistry, College of Humanities & Sciences, Nihon University, Setagaya, Tokyo, Japan. takaiida@chs.nihon-u.ac.jp
Nakamori
Ryusei
R
Yabuta
Rie
R
Yada
Satoru
S
Takagi
Yuzuru
Y
Mano
Nariyasu
N
Ikegawa
Shigeo
S
Goto
Junichi
J
Nambara
Toshio
T
D001647:Bile Acids and Salts / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism*; D005960:Glucosides / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism*; D006001:Glycoconjugates / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D015394:Molecular Structure
D001647:Bile Acids and Salts; D005960:Glucosides; D006001:Glycoconjugates