41162-32-7Relevant academic research and scientific papers
Molecular sieves mediated green per-O-acetylation of carbohydrate templates and lipase catalyzed regioselective alcoholysis of 2,3,5-Tri-O-acetyl-D-ribonolactone
Cardozo, Herbert M.,Ribeiro, Thaís F.,Sá, Marcus M.,Sebr?o, Damianni,Nascimento, Maria G.,Silveira, Gustavo P.
, p. 755 - 764 (2015/04/14)
The per-O-acetylation of D-ribono-1,4-lactone and representative carbohydrates through the combination of acetic anhydride and molecular sieves under solvent-free conditions is demonstrated. The use of 13X/KCl molecular sieves as the heterogeneous catalyst was found to be more efficient than the excess of pyridine normally employed in the conventional method, giving high yields of the expected peracetylated product after 3 h at 25 °C or 1 h at 50 °C. The transformation can be carried out in gram scale and in an open flask. Additionally, the catalyst is readily separated from the reaction medium and can be reutilized without significant loss of activity. This green procedure for acetylation was extended to D-ribonolactone derivatives and natural carbohydrates. To demonstrate the synthetic utility of the method, 2,3,5-tri-O-acetyl-D-ribonolactone was selected as the substrate for the regioselective alcoholysis of acetyl group catalyzed by Candida antarctica lipase B in EtOH to selectively produce 2,3-di-O-acetyl-D-ribonolactone in gram scale.
Regioselective acylation of d-ribono-1,4-lactone catalyzed by lipases
Sebr?o, Damianni,Sá, Marcus M.,Nascimento, Maria Da Graa
experimental part, p. 551 - 556 (2012/01/13)
Lipases from ten different sources and two mycelium-bound lipases isolated from Amazonian fungi were screened as biocatalysts in the acylation reaction of d-ribono-1,4-lactone with a variety of acyl donors in non-aqueous media. Several reaction parameters were evaluated including the type and amount of enzyme, acyl donor, and organic solvent, as well as the influence of water and the recyclability of the catalyst. When Candida antarctica lipase (CAL-B) was used, the acylation was highly regioselective and the corresponding 5-acyl-d-ribono-1,4-lactones were observed as the sole product. The best conversion (>99%) into 5-acetyl-d-ribono-1,4-lactone was obtained through the combination of vinyl acetate as the acetyl donor and 10 mg (100 U) of CAL-B in dry acetonitrile after 24 h. However, lipases from Burkholderia cepacia (PSL-C and PSL-D), Pseudomonas fluorescens (AK) and Thermomyces langinosus (Lipozyme TL-IM) gave mixtures of mono-, di- and tri-acetylated products in lower conversions. CAL-B maintained its catalytic activity during five cycles of repeated use when decanoic and dodecanoic acids were employed as acyl donors in the acylation of d-ribono-1,4-lactone.
Synthesis of 1′-fluorouracil nucleosides as potential antimetabolites
Kodama, Tetsuya,Matsuda, Akira,Shuto, Satoshi
, p. 10011 - 10017 (2007/10/03)
The first synthesis of 1′-fluoronucleosides, which has long been synthetic targets as the potential antimetabolites, was achieved. Electrophilic fluorination of the 1′-position occurred to form an anomeric mixture of 1′-fluorouridine derivatives, when the
A Convenient Procedure for the Deoxygenation and Homologation of D-Ribose Derivatives
Attwood, Stephen V.,Barrett, Anthony G.M.
, p. 1315 - 1322 (2007/10/02)
5-O-Acetyl- and 5-O-diphenyl-t-butylsilyl-2,3-di-O-acetyl-D-ribonolactones were converted into the corresponding 3-deoxy-2-O-acetyl-D-arabinolactone derivatives (9a) and (9b) by sequential reaction with 1,8-diazabicycloundec-7-ene and hydrogen over
Preparation of 3-Deoxy-aldonolactones by Hydrogenolysis of Acetylated Aldonolactones
Bock, Klaus,Lundt, Inge,Pedersen, Christian
, p. 155 - 162 (2007/10/02)
Acetylated aldono-1,4-lactones, when treated with hydrogen in the presence of triethylamine and palladium on carbon, form acetylated 3-deoxy-aldono-1,4-lactones in high yield through elimination of the 3-acetoxy group and subsequent stereospecific hydrogenation of the unsaturated intermediate.Thus, acetylated D-galactono-1,4-lactone (1) yields tri-O-acetyl-3-deoxy-D-xylo-hexono-1,4-lactone (3a).Acetylated D-mannono- or D-glucono-1,4-lactone both give 3-deoxy-D-arabino-hexono-1,4-lactone (10a), whereas the four acetylated D-pentono-1,4-lactones (14-17) all afford di-O-acetyl-D-threo-pentono-1,4-lactone (18a).D-Gluconolactone can be converted into (R)-γ-caprolactone (27) on treatment with hydrogen bromide followed by a series of reductions.Similarly, D-lyxonolactone produces 2,3-dideoxy-D-glycero-pentono-1,4-lactone (29).
