107265-56-5Relevant articles and documents
Total Synthesis of a Densely Functionalized Plesiomonas shigelloides Serotype 51 Aminoglycoside Trisaccharide Antigen
Qin, Chunjun,Schumann, Benjamin,Zou, Xiaopeng,Pereira, Claney L.,Tian, Guangzong,Hu, Jing,Seeberger, Peter H.,Yin, Jian
supporting information, p. 3120 - 3127 (2018/03/08)
Plesiomonas shigelloides, a pathogen responsible for frequent outbreaks of severe travelers' diarrhea, causes grave extraintestinal infections. Sepsis and meningitis due to P. shigelloides are associated with a high mortality rate as antibiotic resistance increases and vaccines are not available. Carbohydrate antigens expressed by pathogens are often structurally unique and are targets for developing vaccines and diagnostics. Here, we report a total synthesis of the highly functionalized trisaccharide repeating unit 2 from P. shigelloides serotype 51 from three monosaccharides. A judicious choice of building blocks and reaction conditions allowed for the four amino groups adorning the sugar rings to be installed with two N-acetyl (Ac) groups, rare acetamidino (Am), and d-3-hydroxybutyryl (Hb) groups. The strategy for the differentiation of amino groups in trisaccharide 2 will serve well for the syntheses of other complex glycans.
MULTIBIOTIC AGENTS AND METHODS OF USING THE SAME
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Page/Page column 109, (2019/01/06)
Multibiotic agents are disclosed. The multibiotic agents may contain two or more moieties linked through bonds cleavable in vivo. The bonds cleavable in vivo can be ester bonds, amide bonds, azo bonds, glycosidic bonds, carbonate linkers, or carbamate linkers. The moieties can be alcohol cores, amine cores, and/or acyls. Also disclosed are compositions containing multibiotic agents and methods of using the multibiotic agents.
Mechanistic studies of highly regioselective decarboxylative-prenyl migration reactions of prenyloxycarbonyl-diketo-dioxinones
Anderson, Katie,Laclef, Sylvain,Barrett, Anthony G.M.
, p. 5569 - 5579 (2015/03/30)
Mechanistic studies of tandem regioselective decarboxylation, prenyl transfer, and aromatization reactions of prenyl dioxinone diketo-carboxylates to provide 3-prenyl-resorcylate derivatives are described. Studies of the effects of concentration and the b
Synthesis and structure of linear and cyclic oligomers of 3- hydroxybutanoic acid with specific sequences of (R)- and (S)-configurations
Bachmann, Beat M.,Seebach, Dieter
, p. 2430 - 2461 (2007/10/03)
To study the stereoselectivity of enzymatic cleavage of poly(3- hydroxybutyrates) (PHB) in a well-defined system (purified depolymerase and monodisperse substrate of specific relative configuration), linear and cyclic oligomers of HB (OHBs) containing (R)- and (S)-3-hydroxybutanoate residues were synthesized. The starting material (R)-HB was prepared from natural sPHB, and (S)-HB by enantioselective reduction of 3- oxobutanoate with yeast or with H2/Noyori-Taber catalyst (Scheme2). The HB building blocks were then prolected (O-benzyl/tert-butyl ester; Scheme 3) and coupled to give dimers 3, 4, tetramers 5-9, and octamers 10-18; for analytical comparison, a 3mer, 5mer, 6mer, and 7mer (19-22) were also prepared. Two of the tetramers were subjected to macrolactonization conditions (Yamaguchi) to give the cyclic tetramers 23 and 25 and octamers 24 and 26. All new compounds were fully characterized (m.p., [α](D), CD, IR, 1H- and 13C-NMR, MS, elemental analysis). Single-crystal X-ray structure analyses were performed with oligolides 24 and 25 (Figs. 2 and 4), and the structures, as well as the crystal packing, were compared with those of analogs containing only (R)-HB units or consisting of 3-amino- instead of 3-hydroxybutanoic-acid moieties.
Monodisperse linear and cyclic oligo[(R)-3-hydroxybutanoates] containing up to 128 monomeric units
Lengweiler, Urs D.,Fritz, Monica G.,Seebach, Dieter
, p. 670 - 701 (2007/10/03)
Using benzyl ester/(tert-butyl)diphenylsilyl ether protection, (COCl)2/pyridine esterification conditions, and a fragment-coupling strategy (with H2/Pd-C debenzylation and HF-pyridine desilylation), linear oligomers of (R)-3-hydroxyb
Cyclische Oligomere von (R)-3-Hydroxybuttersaeure: Herstellung und strukturelle Aspekte
Plattner, Dietmar A.,Brunner, Andreas,Dobler, Max,Mueller, Hans-Martin,Petter, Walter,et al.
, p. 2004 - 2033 (2007/10/02)
Cyclic Oligomers of (R)-3-Hydroxybutanoic acid: Preparation and Structural Aspects The oligolids containing three to ten (R)-3-hydroxybutanoate (3-HB) units (12 through 40-membered rings 1-8) are prepared from the hydroxy acid itself, its methylester, its lactone ('monolide') or its polymer (poly(3-HB), mol. wt. ca. 106 Dalton) under three sets of conditions: i) treatment of 3-HB (10) with 2,6-dichlorobenzoyl chloride/pyridine and macrolactonization under high dilution in toluene with 4-(dimethylamino)pyridine (Fig.3); ii) heating a solution (benzene, xylene) of the β-lactone 12 or of the methyl ester 13 from 3-HB with the tetraoxadistanna compound 11 as trans-esterification catalyst (Fig.4); iii) heating a mixture of poly(3-HB) and toluene-sulfonic acid in toluene/1,2-dichloroethane for prolonged periods of time at ca. 100 deg (Fig.6).In all three cases, mixtures of oligolides are formed with the triolide 1 being the prevailing component (up to 50percent yield) at higher temperatures and with longer reaction times (thermodynamic control, Fig.3-6).Starting from rac-β-lactone rac-12, a separable 3:1 to 3:2 mixture of the l,u- and l,l-triolide diastereoisomers rac-14 and rac-1,respectively, is obtained.An alternative method for the synthesis of the octolide 6 is also described: starting from the appropriate esters 15 and 17 and the benzyl ether 16 of 3-HB, linear dimer, tetramer, and octamer derivatives 18-23 are prepared, and the octamer 23 with free OH and CO2H group is cyclised (->6) under typical macrolactonization conditions (see Scheme).This 'exponential fragment coupling protocol' can be used to make higher linear oligomers as well.The oligolids 1-8 are isolated in pure form by vacuum distillation, chromatography, and crystallization, an important analytical tool for determining the composition of mixtures being 13C-NMR spectroscopy (each oligolide has a unique and characteristic chemical shift of the carbonyl C-atom with the triolide 1 at lowest, the decolide 8 at highest field).The previously published X-ray crystal structures of triolide 1, pentolide 3, and hexolide 4 (two forms), as well as those of the l,u-triolide rac-14, of tetrolide ent-2, of heptolide 5, and of two modifications of octolide 6 described herein for the first time are compared with each other (Figs.7-10 and 12-15, Tables 2 and 5-7) and with recently modelled structures (tables 3 and 4, Fig.11).The preferred dihedral angles τ1 to τ4 found along the backbone of nine oligolide structures (the hexamer and the larger ones have folded rings!) are mapped and statistically evaluated (Fig.16, Tables 5-7).Due to the occurrence of two conformational minima of the dihedral angle O-CO-CH2-CH (τ3 = +151 or -43 deg), it is possible to locate two types of building blocks for helices in the structures at hand: a right-handed 31 and a left-handed 21 helix; both have a ca. 6 Angstroem pitch, but very different shapes and dispositions of the carbonyl groups (Fig.17)....
18. High-Yield Synthesis of 20-, 24-, and 28-Memebered Macropentolide, -hexolide, and -heptolide, Respectively, from (R)- or (S)-3-Hydroxybutanoic Acid under Yamaguchi's Macrolactonization Conditions
Seebach, Dieter,Braendli, Urs,Schnurrenberger, Peter,Przybylski, Michael
, p. 155 - 167 (2007/10/02)
The macrocyclic pentolide 1, hexolide 2, and heptolide 3 constitute ca. 80percent of the oligomers formed in ca. 50percent yield from enantiomerically pure 3-hydroxybutanoic acid under Yamaguchi's macrolactonization conditions.The FAB mass spectra of the
