4451-35-8Relevant articles and documents
The reactions of β- and α-pyranose peracetates with PCl5, and utilization of the products to construct sarsasapogenin glycosides
Saito,Ichinose,Sasaki,Sumita
, p. 3261 - 3268 (1992)
The reactions of β- and α-pyranose peracetates with PCl5 gave products regioselectively chlorinated. The reactions of 1,2,3,4,6-penta-O-acetyl-β-D-glucopyranose (5) and -β-D-galactopyranose (6) with PCl5 in CCl4 and that of methyl 2,3,4-tri-O-acetyl-β-D-glucuronatopyranose (7) with PCl5 in toluene gave 2-O-trichloroacetyl-β-D-pyranosyl chlorides 4, 12 and 14, respectively, as major products, and α-D-pyranosyl chlorides 11, 13 and 15, respectively, as minor products. On the other hand, the reactions of compounds 8 and 9 which were α-anomers of 5 and 6, respectively, with PCl5 gave as major products transformed acetyl groups at C-6 to -C(Cl) = CCl2 or -C(Cl)2-CCl3 group (16 and 17 from 8 and 18 from 9). The same reaction of 10, which was α-anomer of 7, gave α-chloride 15 as a major product. The glycosidation of sugar derivative 4 with sarsasapogenin 23 gave β-glycoside 24 (29.1%) and α-glycoside 25 (46.9%), and that of 12 with 23 gave β-glycoside 26 (24.0%) and α-glycoside 27 (40.8%). The improvement of the yields of β-glycosides 24 and 26 (66.9 and 62.1% for 24 and 26, respectively) in the glycosidations were accomplished by the employment of α-bromides 28 and 29 obtained from 4 and 6, respectively. The glycosidations of monoglycosides 30 and 31 obtained by the treatment 24 and 26, respectively, with ammonia-saturated ether with sugar acetate bromides 32 and 34 gave diglycoside derivatives 35 and 33, respectively.
2-Trimethylsilylethyl glycosides. Treatment with electrophilic reagents to give trimethylsilyl- and methoxymethyl glucopyranosides and glucopyranosyl chloride
Jansson, Karl,Magnusson, Goeran
, p. 59 - 64 (1990)
Treatment of 2-trimethylsilylethyl 2346-tetra-O-acetyl-β-D-glucopy ranoside (-1) with trimethylsilyl trifluoromethanesulfonate trifluoromethanesulfonic acid or borontrifluoride etherate in the presence ofdimethoxymethane gave methoxymethyl 2346-tetra-O-acetyl-β-D-glucopyranoside in 54 62 and 66% yield respectively. In the absence of dimethoxymethane trimethylsilyl 2346-tetra-O-acetyl-β-D-glucopyranoside was formed in 78% yield. Treatment of I with 11-dichloromethylmethyl ether in the presence of zinc chloride gave 2346-tetra-O-acetyl-α-D-glucopyranosyl chloride in 98% yield.
Stereoselective Preparation of C-Aryl Glycosides via Visible-Light-Induced Nickel-Catalyzed Reductive Cross-Coupling of Glycosyl Chlorides and Aryl Bromides
Mou, Ze-Dong,Wang, Jia-Xi,Zhang, Xia,Niu, Dawen
supporting information, p. 3025 - 3029 (2021/05/27)
A nickel-catalyzed cross-coupling reaction of glycosyl chlorides with aryl bromides has been developed. The reaction proceeds smoothly under visible-light irradiation and features the use of bench-stable glycosyl chlorides, allowing the highly stereoselective synthesis of C-aryl glycosides. (Figure presented.).
From Glucose to Polymers: A Continuous Chemoenzymatic Process
Banahene, Nicholas,Bettinger, Reuben,Du, Wenjun,Esser-Kahn, Aaron P.,Liang, Zhijie,Maiti, Sampa,Manna, Saikat,Pham, Lucynda,Wang, Jun,Xu, Yi,Zientko, John
supporting information, p. 18943 - 18947 (2020/08/25)
Efforts to synthesize degradable polymers from renewable resources are deterred by technical and economic challenges; especially, the conversion of natural building blocks into polymerizable monomers is inefficient, requiring multistep synthesis and chromatographic purification. Herein we report a chemoenzymatic process to address these challenges. An enzymatic reaction system was designed that allows for regioselective functional group transformation, efficiently converting glucose into a polymerizable monomer in quantitative yield, thus removing the need for chromatographic purification. With this key success, we further designed a continuous, three-step process, which enabled the synthesis of a sugar polymer, sugar poly(orthoester), directly from glucose in high yield (73 % from glucose). This work may provide a proof-of-concept in developing technically and economically viable approaches to address the many issues associated with current petroleum-based polymers.
Chemoenzymatic synthesis of arabinomannan (AM) glycoconjugates as potential vaccines for tuberculosis
Li, Zhihao,Bavaro, Teodora,Tengattini, Sara,Bernardini, Roberta,Mattei, Maurizio,Annunziata, Francesca,Cole, Richard B.,Zheng, Changping,Sollogoub, Matthieu,Tamborini, Lucia,Terreni, Marco,Zhang, Yongmin
supporting information, (2020/07/27)
Mycobacteria infection resulting in tuberculosis (TB) is one of the top ten leading causes of death worldwide in 2018, and lipoarabinomannan (LAM) has been confirmed to be the most important antigenic polysaccharide on the TB cell surface. In this study, a convenient synthetic method has been developed for synthesizing three branched oligosaccharides derived from LAM, in which a core building block was prepared by enzymatic hydrolysis in flow chemistry with excellent yield. After several steps of glycosylations, the obtained oligosaccharides were conjugated with recombinant human serum albumin (rHSA) and the ex-vivo ELISA tests were performed using serum obtained from several TB-infected patients, in order to evaluate the affinity of the glycoconjugate products for the human LAM-antibodies. The evaluation results are positive, especially compound 21 that exhibited excellent activity which could be considered as a lead compound for the future development of a new glycoconjugated vaccine against TB.
