59055-58-2Relevant articles and documents
Nuclear Magnetic Resonance Study on Glycolsyl Esters: Glycosyl Esters of 3-O-Acetyloleanolic Acid and Octanoic Acid
Mizutani, Kenji,Ohtani, Kazuhiro,Kasai, Ryoji,Tanaka, Osamu,Matsuura, Hiromichi
, p. 2266 - 2272 (2007/10/02)
α-L-Rhamnosyl, α-L-arabinosyl, 2'-O-β-D-glucosyl-α-L-arabinosyl and 2'-O-α-L-rhamnosyl-α-L-arabinosyl esters of octanoic acid and β-D-xylosyl, α-L-rhamnosyl, α-L-arabinosyl, 2'-O-β-D-glucosyl-α-L-arabinosyl and 2'-O-α-L-rhamnosyl-α-L-arabinosyl esters of 3-O-acetyloleanolic acid were synthesized.The nuclear magnetic resonance spectra of sugar moieties of the esters of 3-O-acetyloleanolic acid, which is a represantative sterically hindered carboxylic acid, were compared with those of the corresponding less-hindered glycosyl esters of octanoic acid.In the case of rhamnose and arabinose, the displacements of sugar carbon signals on acylation of the anomeric hydroxyl group are similar to those already observed for fatty acid glucosyl esters regardless of the steric hindrance of the acyl group.However, the 2-O-glycosylation shifts of 1-O-acyl-α-L-arabinopyranose were found to depend upon the steric hindrance of the acyl groups.The anomalous 2'-O-glycosylation shifts of arabinosyl carbon signals of α-L-arabinosyl 3-O-acetyl-oleanolate were not observed in the case of α-L-arabinosyl octanoate.Keywords---- glycosyl ester synthesis; reducing terminal protecting group; tert-butyl glycoside; glycosyl octanoate; glycosyl 3-O-acetyloleanolate; NMR glycosylation shift; 1-O-acyl-2-O-glycosyl-α-L-arabinose NMR; 2-O-glycosyl-arabinopyranoside ring conformation.