Acetylated methyl glucopyranuronate trichloroacetimidate as a glycosyl donor for efficient synthesis of disaccharides

Identification of some benproperine metabolites in humans and investigation of their antitussive effect1

“…The salt form of the basic acceptor was better than its free form for glucuronidation, with Lewis acid used as the promoter in the present study. When trimethysilyl trifluoromethane sulfonate (TMSOTf) [9] was used as a promoter instead of BF 3 ×Et 2 O, more of the byproduct, 2 acetylate, was obtained and the yield of the desired product was increased. An inverse addition, which means trichloroacetimidate 7 was added into the mixed solution of 2 phosphate and BF 3 ×Et 2 O, improved the yield to 52% from 21%.…”

“…3-Piperidinol hydrochloride and 4-piperidinol were obtained from the Aldrich Chemical Co. We prepared 1-[2-(phenylmethyl)phenoxy]-2-propanol p-toluensulfonate (6) ourselves, according to published procedures [7,8] , from obenzylphenol, which was kindly supplied by Aosen Pharmaceutical Co. Methyl (2,3,4-tri-O-acetyl-1-O-trichloroacetimidoyl)-α-D-glucopyranuronate (7) was prepared by us, according to Soliman et al [9] from D(+)-glucuronolactone, which was obtained from Wako Chemical Co. The structures of 6 and 7 were identified using 1 H and 13 C NMR.…”

“…BF 3 Et 2 O (10 µL) was added to in one portion. After 10 min of stirring, methyl (2,3,4-tri-O-acetyl-1-O-trichloroacetimidoyl)-α-Dglucopyranuronate (7) [9] (95 mg, 0.20 mmol) was added. Stirring was continued for 48 h at an ambient temperature.…”

Synthesis of Glycosides of Glucuronic, Galacturonic and Mannuronic Acids: An Overview

“…A strategy for the synthesis of the target disaccharides [ 53 ], was the selection of the glucosyluronic donor. Selective O -deacetylation of methyl 1,2,3,4-tetra- O -acetyl-β- D -glycopyranuronate using hydrazinium acetate gave methyl 2,3,4-tri- O -acetyl- D -glucopyranuronate 67 , followed by treatment with trichloroacetonitrile and 1,8-diazabicyclo[5,4,0]-undec-7-ene (DBU) to form the crystalline imidate 28 in good yield.…”

C-Glycoside D-galacturonates suitable as glycosyl acceptors for the synthesis of allyl C-homo- and rhamno-galacturonan modules

“…As shown in Scheme 5, the rhamnopyranose donors 21αβ were coupled with the C-glycoside galacturonate acceptors 4 in a ratio of 1.1:1 in the presence of trimethylsilyl trifluoromethanesulfonate. [10][11][12] This coupling produced the desired α-(1→4)-coupled disaccharide 23 in 18% yield, 21α/β (donors) in 26% yield, and the accompanying transesterfication 21,22 product of the acceptor 25 in 23% yield. To improve the yield of the disaccharide 23, the bromide donor 22 was synthesized from compounds 21α/β by the reaction with oxalyl bromide in dry dichloromethane to give the bromosugar 22 (Scheme 4) in 95% yield.…”