40269-01-0Relevant articles and documents
Stereoselective synthesis of resorcylic acid lactone Cochliomycin B
Nagalatha,Siva Ganesh,Venkat Narsaiah
, (2021/09/22)
The total synthesis of 14-membered resorcylic acid lactone, Cochliomycin B has prescribed, in a convergent manner, from readily available starting materials, D-galactose, L-aspartic acid and ethyl acetoacetate. The key reactions involved in the synthesis are Julia-Kocienski olefination, E-selective Horner-Wadsworth-Emmons olefination and intramolecular lactonization.
Regioselectivity of glycosylation reactions of galactose acceptors: An experimental and theoretical study
Del Vigo, Enrique A.,Stortz, Carlos A.,Marino, Carla
supporting information, p. 2982 - 2989 (2020/01/09)
Regioselective glycosylations allow planning simpler strategies for the synthesis of oligosaccharides, and thus reducing the need of using protecting groups. With the idea of gaining further understanding of such regioselectivity, we analyzed the relative
Localization-controlled two-color luminescence imaging: Via environmental modulation of energy transfer in a multichromophoric species
Bonaccorsi, Paola,Papalia, Teresa,Barattucci, Anna,Salerno, Tania M. G.,Rosano, Camillo,Castagnola, Patrizio,Viale, Maurizio,Monticone, Massimiliano,Campagna, Sebastiano,Puntoriero, Fausto
supporting information, p. 4733 - 4738 (2018/04/03)
We prepared a bichromophoric species 1, made of two different bodipy dyes bridged by a d-galactose unit. 1 exhibits different emission spectra when located in different compartments of biological systems, independently of its concentration. This is an unprecedented feature for a single multicomponent molecule and is due to the dependence on the environment of the photoinduced energy transfer process occurring between its bodipy subunits. Therefore, 1 can give useful information about cell composition and ultimately anomalies without requiring the simultaneous use of several different compounds, paving the way for the use of environment-controlled inter-component energy transfer to gain cell information based on luminescence imaging.
A novel O-fucosylation strategy preactivated by (p-Tol)2SO/Tf2O and its application for the synthesis of Lewis blood group antigen Lewisa
Li, Cui-yun,Liu, Guang-jian,Du, Wei,Zhang, Yuan,Xing, Guo-wen
supporting information, p. 2109 - 2112 (2017/05/09)
Based on a preactivation strategy using (p-Tol)2SO/Tf2O, a new O-fucosylation method with thioglycoside as donor under mild conditions was reported. High yields and excellent α-stereoselectivities of the fucosylation were obtained wi
Allylic Azide Rearrangement in Tandem with Huisgen Cycloaddition for Stereoselective Annulation: Synthesis of C-Glycosyl Iminosugars
Moynihan, Lorna,Chadda, Rekha,McArdle, Patrick,Murphy, Paul V.
supporting information, p. 6226 - 6229 (2016/01/09)
Allylic azide rearrangement is used in tandem with intramolecular azide-alkene cycloaddition to give a triazoline that when subsequently decomposed in the presence of a nucleophile gives piperidines. The tandem reaction gives two stereocenters that are generated with high control. The formation of the piperidines required the presence of innate conformational constraint. The applicability of the annulation reaction is demonstrated by the synthesis of iminosugars. A proposal is included to account for the observed stereoselectivity, which is influenced by the precursor structure.
Linearization of carbohydrate derived polycyclic frameworks
Singh, Priyanka,Panda, Gautam
, p. 31892 - 31903 (2014/08/18)
We report easy access to carbohydrate derived diverse tricyclic skeletons which could be beneficial for exploring polyfunctionalized chiral alicycles. The key reaction to assemble a sugar fused tricyclic core is intermolecular tandem esterification and 1,3-dipolar cycloaddition. The framework was elaborated using amide forming reactions, opening of isoxazolidine rings followed by N and O-acylations. The sequences provide distinct, spatially separated and encoded chemical entities that may pave the way to investigate cell functions.
Lipases in the regioselective preparation of glyceric acid esters of methyl glycosides
Sundell, Riku,Kanerva, Liisa T.
supporting information, p. 4971 - 4978 (2013/08/23)
The lipase-catalyzed regioselective acylation of methyl α-D-galacto-, -gluco- and -mannopyranosides with isopropylidene-protected (R)- and (S)-glyceric acid methyl esters in organic solvents is presented. Factors affecting the formation of the 6-O-mono- and 2,6-O-diacylated products are examined and preparative-scale reactions are detailed. In addition, studies on partially protected methyl α-D-galactopyranosides are presented, with the 3,4-O-isopropylidene protected compound leading exclusively to the formation of the 6-O-monoacylated product even at high substrate concentrations. Application of acidic resin in methanol allows removal of the isopropylidene protection groups without disturbing the ester bond at C-6. Copyright
Nano n-propylsulfonated magnetic γ-Fe 2O 3 as an efficient and reusable catalyst for the synthesis O-isopropylidene derivatives of carbohydrates
Zhang, Xiaoran,Zhang, Changqiang
, p. 249 - 258 (2013/08/15)
Nano n-propylsulfonated γ-Fe2O3 was found to be a highly efficient, reusable heterogeneous catalyst for the conversion of a range of monosaccharides and some of their derivatives to the corresponding O-isopropylidene derivatives in good to excellent yields by refluxing the reaction mixture in dry acetone. The magnetic property of the catalyst enabled its separation from the reaction mixture by a simple process of filtration along with the aid of an external magnet. The efficiency of the catalyst was found to be largely unaffected for at least up to six cycles of reuse, thus proving the new methodology to be environmentally rewarding besides being simple and facile in operation.
Hydroxy group acidities of partially protected glycopyranosides
Matwiejuk, Martin,Thiem, Joachim
experimental part, p. 2180 - 2187 (2012/06/30)
A comprehensive acidity study of carbohydrate hydroxy groups has been carried out. Relative acidities (Ke) were determined spectrophotometrically for partially methylated methyl α-D- glycopyranosides. Apparently, the acidity is strongly affected by intramolecular hydrogen bonding as well as stereochemistry and solvation. By comparison with pKe and pKa values of aliphatic alcohols and polyols the first estimation of the pKa values for partially protected glycopyranosides was obtained. These findings contribute to the understanding of the relative reactivities of carbohydrate hydroxy groups.
A chiron approach to aminocytitols by petasis-borono-mannich reaction: Formal synthesis of (+)-conduramine e and (-)-conduramine e
Ghosal, Partha,Shaw, Arun K.
supporting information, p. 7627 - 7632,6 (2020/08/24)
A chiron approach to a stereoselective route for the synthesis of aminocytitols from carbohydrates is described. The formal synthesis of (+)-conduramine E and (-)-conduramine E was achieved by utilizing this strategy. The key features of the synthetic strategy include one-pot three-component Petasis-Borono-Mannich reaction to introduce the syn-β-amino alcohol functionality of conduramine E and ring-closing metathesis to construct its carbocyclic core. The present synthetic approach paves the way for stereoselective synthesis of several conduramines starting from carbohydrates.