The synthesis of a UDP-Galf analog incorporating 1,4-dideoxy-1,4-imino-d-galactitol skeleton alpha-linked to UMP by 3C-tether and series related pyrrolidine galactofuranose mimicks is reported. These compounds were obtained way the highly stereoselective reaction silylated nucleophiles with N-Cbz glucofuranosylamine which afforded corresponding open-chain product 1,2-syn stereochemistry, as predicted from pionneering studies Kobayashi. Cyclization these intermediates alpha-C-glycosides...

The etherification of sucrose in aqueous solutions is performed via butadiene telomerization catalysed by palladium complexes. degree substitution evaluated from a combination analytical techniques including NMR and LSIMS as well chromatographic gravimetric measurements. Degrees ranging 1 to 6 are obtained depending upon the experimental conditions, particularly temperature, butadiene/sucrose ratio nature catalyst. Thus, precursor salt use optimum amounts TPPTS ligand shown be critical...

Association of chiral [CuL2]+ complexes (L = 2-R-phen, 6-R-bpy, and 2-iminopyridine) with TRISPHAT (tris(tetrachlorobenzenediolato)phosphate(V)) anion leads to NMR enantiodifferentiation, which can be used determine the kinetics racemization complexes.

Tetra-O-benzyl-d-glucofuranose was converted into uridine diphosphono-β-Galf mimics based on an iminosugar skeleton linked to UMP by a 2-hydroxypropyl tether. The synthesis is the highly regio- and stereoselective cycloaddition of original uridin-5'-yl allylphosphonate with 1,4-dideoxy-1,4-iminogalactitol-derived cyclic nitrone, followed reductive elaboration product. resulting iminogalactose−UMP conjugates are novel sugar nucleotide which could be useful as inhibitors UDP-Gal mutase...

Association of enantiopure TRISPHAT anion (1) with chiral spiro [Cu(LL′)2] complexes (LL′ = 2-R-phen, 2, 6-R-bpy, 3, and 2-iminopyridine, 4) leads to an efficient NMR enantiodifferentiation. Variable temperature 1H spectroscopy has been used determine the isomerisation kinetics these pseudo-tetrahedral evaluate their configurational stability; latter depending on structure diimine ligands. In case 2-anthracenyl-phen derivative, a decent level supramolecular stereocontrol was noted (d.e. up...

An NHC-catalyzed sila-Stetter reaction between aliphatic acylsilanes and vinylketones bearing silyl ether substituents affords functionalized 1,4-diketones, which upon treatment under acidic conditions leads to the corresponding bis-spiroacetals. The two-step sequence may also be carried out in a one-pot operation leading high yields of desired

A nucleotide–lipids family featuring the four natural nucleobases was explored through their self-assembly properties.

[reaction: see text] Various alpha-C-substituted 1,4-dideoxy-1,4-imino-d-galactitols were prepared efficiently from 1-O-acetyl-2,3,5,6-tetra-O-benzyl-d-glucofuranose by a four-step sequence involving as the key step highly syn-selective TMSOTf-catalyzed addition of silylated nucleophiles to glycofuranosylamine. Cross-metathesis alpha-C-allylated iminogalactofuranose derivative with an original uridin-5'-yl vinylphosphonate led novel UDP-galactofuranose mimics. Such compounds are interest...

Abstract Synthesis of the bis‐spiroacetal core 13‐desmethyl spirolide C has been completed based on a sila‐Stetter‐acetalization process. The acylsilane and enone partners in Stetter reaction were prepared 7 11 steps, respectively, from ( S ) R )‐aspartic acid. quaternary center at C19 moiety was controlled by relying Seebach’s chiral self‐reproduction method using an enantiopure )‐lactic acid dioxolanone. final acid‐catalyzed spiroacetalization provided desired spiroacetal as mixture...

2,3,5-Trisubstituted tetrahydrofurans were prepared stereoselectively through a two-step process involving the addition of an acyl radical to β-silyloxy acrylic ester followed by acid-catalyzed desilylation–ketalization sequence and final oxocarbenium reduction step. High levels 1,2- 1,3-stereocontrol attained when (Me3Si)3SiH was used as ionic hydrogen transfer agent.

Most proteomic labelling technologies intend to improve protein quantification and/or facilitate (de novo) peptide sequencing. We present here a novel stable-isotope method simultaneously identify and quantify components in complex mixtures by specifically derivatizing the N-terminus of proteins with 4-sulphophenyl isothiocyanate (SPITC). Our approach combines identification through differential isotope-coded at prior digestion. The isotope spacing 6 Da (unlabelled vs. six-fold 13C-labelled...

The multimerization of active compounds has emerged as a successful approach, mainly to address the multivalency numerous biological targets. Regarding pharmaceutical prospect, carrying several ingredient units on same synthetic scaffold was practical approach enhance drug delivery or activity with lower global concentration. Various examples have highlighted better in vivo stability and therapeutic efficiency through sustained action over monomeric molecules. synthesis strategy aims...

The commercial synthesis of Ambrox® is modified so that the key intermediate, sclareolide, results from an indirect oxidative degradation sclareol. This method allows to greatly alleviate waste disposal problem and raise overall yield 75%.

Abstract 7‐Silyl‐ and 7‐silylmethylcycloheptatrienes were shown to react with acylnitroso reagents at room temperature, through their norcaradiene forms, generate the corresponding cycloadducts 5 a – b 6 as single diastereomers. The course of reaction was dramatically modified by changing conditions. Using polar medium, functionalized cyclohexa‐1,3‐dienes 7 bicyclic compounds 13 instead generated, incorporating one or two amino groups. Similar behavior observed using other dienophiles,...

ADVERTISEMENT RETURN TO ISSUEPREVLetterNEXT7-Silylcycloheptatrienes and Analogues: Reactivity Selectivity in Cascade ProcessesRedouane Beniazza, Valérie Desvergnes, Yannick Landais*View Author Information University Bordeaux 1, Institut des Sciences Moléculaires, UMR-CNRS 5255, 351, cours de la libération, 33405 Talence cedex 05, France[email protected]Cite this: Org. Lett. 2008, 10, 19, 4195–4198Publication Date (Web):September 2008Publication History Received18 July 2008Published online10...

Desymmetrization of 7-silylcycloheptatriene through consecutive dihydroxylation and acyl-nitroso cycloaddition the resulting diene moiety is described. Dihydroxylation occurred anti relative to resident silicon group in line with previous observations made cyclohexadiene series. In contrast, subsequent poor regiocontrol but good level diastereocontrol syn bulky silyl substituent. The cycloadducts were then elaborated further provide a straightforward entry toward aminocycloheptitols ten...