Convenient Per-O-Acetylation of Monosaccharides with Vinyl Acetate/ Na3PO4-H2O

Abstract

Several monosaccharides were peracetylated in excellent isolated yields (89-100%) with vinyl acetate in aqueous Na 3 PO 4 . The per-O-acetylation reaction is fast and mild, as well as insensitive to water. Meanwhile, the workup is convenient and the catalyst can be recycled easily.

Enumeration of hydroxyl groups of sugars and sugar alcohols by aqueous‐based acetylation and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry

“…Recently, Shi and coworkers reported the results of a study that showed excellent total derivatization of hydroxyl groups. [7] In this study, the reported method has been modified to obtain all the partial and fully derivatizated products of hydroxyl group containing analytes. In brief, about 2 mg of sample were dissolved in a vial containing 20 mL of vinyl acetate and 100 mL of 3% Na 3 PO 4 buffer solution at room temperature (pH of approximately 12).…”

“…[3] Permethylation, peracetylation and trimethylsilylation are commonly used for this purpose. [7][8][9][10][11] Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) has extended the usefulness of mass spectrometry in recent years. This technique, unlike electron impact (EI) ionization, generally gives molecular weight information as sample fragmentation is minimized with the matrix used for MALDI analysis.…”

Biocatalytic Separation of N-7/N-9 Guanine Nucleosides

“…The coupling of 2- N -isobutanoylguanine ( 2 ) with 1,2,3,5-tetra- O -acetyl- d -ribofuranose ( 3 ), , 1,2,3,5-tetra- O -acetyl- d -arabinofuranose ( 4 ), or 1,2,3,5-tetra- O -acetyl- l -arabinofuranose ( 5 ) − in the presence of TMSOTf as Lewis acid catalyst following a standard Vorbrüggen , coupling protocol afforded mixtures of 2,3,5-tri- O -acetylated 9- and 7-β- d -ribofuranosylguanines 6 and 7 , 9- and 7-α- d -arabinofuranosylguanines 8 and 9 , and 9- and 7-α- l -arabinofuranosylguanines 10 and 11 in ratios of 87:13, 63:37, and 76:24, respectively, in 60−65% yields (Scheme and Table ). The ratio of regioisomers N- 9 and N -7 in the above guanine nucleoside mixtures 6 and 7 , 8 and 9 , and 10 and 11 were calculated on the basis of the integration of the corresponding anomeric protons in the 1 H NMR spectra (400 MHz) of the mixtures (Table ).…”

Novos tensoativos oxigenados para fluidos supercríticos

“…Os tensoativos F1A(B) tiveram suas hidroxilas terminais sulfatadas, gerando os tensoativos aniônicos F1A(B)-OSO 3 Na, de acordo com o esquema 3.6. (FAN et al, 2005;MISRA et al, 2005;SHI, 2006) Para a síntese do precursor GA' (esquema 3.9), 30,0 g de GA'' (82 mmol) foram adicionados a uma solução resfriada (0 °C, em banho de gelo) num balão contendo 10,8 g (79 mmol) de cloreto de zinco anidro em 150 mL de Ac 2 O (1,68 mol, 2,5 equivalentes). A solução é mantida no banho de gelo por 1 h, e depois deixada sob agitação durante 24 h a temperatura ambiente.…”