112711-34-9Relevant academic research and scientific papers
Total Synthesis and Biological Evaluation of the Glycosylated Macrocyclic Antibiotic Mangrolide A
Hattori, Hiromu,Roesslein, Joel,Caspers, Patrick,Zerbe, Katja,Miyatake-Ondozabal, Hideki,Ritz, Daniel,Rueedi, Georg,Gademann, Karl
, p. 11020 - 11024 (2018/07/31)
The macrocyclic antibiotic mangrolide A has been described to exhibit potent activity against a number of clinically important Gram-negative pathogens. Reported is the first enantioselective total synthesis of mangrolide A and derivatives. Salient features of this synthesis include a highly convergent macrocycle preparation, stereoselective synthesis of the disaccharide moiety, and two β-selective glycosylations. The synthesis of mangrolide A and its analogues enabled the re-examination of its activity against bacterial pathogens, and only minimal activity was observed.
Synthesis and Applications of Silyl 2-Methylprop-2-ene-1-sulfinates in Preparative Silylation and GC-Derivatization Reactions of Polyols and Carbohydrates
Markovic, Dean,Tchawou, Wandji Augustin,Novosjolova, Irina,Laclef, Sylvain,Stepanovs, Dmitrijs,Turks, Maris,Vogel, Pierre
, p. 4196 - 4205 (2016/03/16)
Trimethylsilyl, triethylsilyl, tert-butyldimethylsilyl, and triisopropylsilyl 2-methylprop-2-ene-1-sulfinates were prepared through (CuOTf)2C6H6-catalyzed sila-ene reactions of the corresponding methallylsilanes with SO2 at 50 °C. Sterically hindered, epimerizable, and base-sensitive alcohols gave the corresponding silyl ethers in high yields and purities at room temperature and under neutral conditions. As the byproducts of the silylation reaction (SO2+isobutylene) are volatile, the workup was simplified to solvent evaporation. The developed method can be employed for the chemo- and regioselective semiprotection of polyols and glycosides and for the silylation of unstable aldols. The high reactivity of the developed reagents is shown by the synthesis of sterically hindered per-O-tert-butyldimethylsilyl-α-d-glucopyranose, the X-ray crystallographic analysis of which is the first for a per-O-silylated hexopyranose. The per-O-silylation of polyols, hydroxy carboxylic acids, and carbohydrates with trimethylsilyl 2-methylprop-2-ene-1-sulfinate was coupled with the GC analysis of nonvolatile polyhydroxy compounds both qualitatively and quantitatively. Regio- and chemoselective silylation of polyols and carbohydrates has been achieved by employing silyl sulfinates (see the picture; TBS=tert-butyldimethylsilyl, TES=triethylsilyl, TIPS=triisopropylsilyl, TMS=trimethylsilyl). The silylation reactions proceed in high yield because the reactions are mild and fast and produce only volatile byproducts. Furthermore, the silyl sulfinates are used as new derivatization reagents for the GC analysis of nonvolatile polyhydroxy compounds.
Tetrabutylammonium nitrite - acetic anhydride system, tetrabutylammonium nitrite, tetrabutylammonium acetate, and cesium acetate - 18-crown-6 for efficient unmasking of alkyl N-phenylcarbamates
Akai, Shoji,Nishino, Noriaki,Iwata, Yukihiro,Hiyama, Jun-Ichi,Kawashima, Etsuko,Sato, Ken-Ichi,Ishido, Yoshiharu
, p. 5583 - 5586 (2007/10/03)
Novel unmasking procedures for alkyl N-phenylcarbamates are established by the use of a tetrabutylammonium nitrite (Bu4NNO2) - acetic anhydride system, Bu4NNO2, Bu4NOAc, and CsOAc 18-crown-6 towards variously functionalized sugar derivatives.
Stereospecific synthesis of branched-chain sugars by a novel aldol-type cyclocondensation
Perez-Perez, Maria-Jesus,Camarasa, Maria-Jose,Diaz-Ortiz, Angel,Felix, Ana San,Heras, Federico G. de las
, p. 399 - 411 (2007/10/02)
A procedure for the preparation of branched-chain sugars having highly functionalised C-branches is reported.Reaction of furanos-3-uloses, pyranos-3-uloses, or pyranos-2-uloses with sodium cyanide followed by mesylation of the corresponding cyanohydrin af
The 'Off-template' Problem: Towards a General Solution
Rashid, Abdul,Taylor, G. Mark,Wood, William W.,Alker, David
, p. 1289 - 1296 (2007/10/02)
Wittig reaction of the t-butyldimethylsilylated C-3 ketone methyl 4,6-O-benzylidene-2-O-(t-butyldimethylsilyl)-α-D-ribo-hexopyranosid-3-uloside leads exclusively to C-2 alkenes, providing an efficient synthesis of these potentially useful intermediates.Alternatively, the corresponding t-butyldiphenylsilyl ether, prepared with complete regiospecificity from methyl 4,6-O-benzylidene-α-D-glucopyranoside, gives a C-3 alkene on oxidation and Wittig reaction.Deprotection, hydrogenation and cyclization of this product leads to the cis-fused butyrolactone, methyl 4,6-O-benzylidene-3-deoxy-3-(ethoxycarbonyl)-2,3-butyrolactone-α-D-allopyranoside, which is alkylated stereospecifically to give methyl 4,6-O-benzylidene-3-deoxy-3-(prop-2-yloxycarbonyl)-2,3-butyrolacto-α-D-allopyranoside.This procedure provides a general solution of the 'off-template' problem of carbohydrate-based natural product synthesis.
THE "OFF-TEMPLATE" PROBLEM: SYNTHESIS AND ALKYLATION OF A FUSED-BUTYROLACTONE FROM D-GLUCOSE
Wood, William W.,Rashid, Abdul
, p. 1933 - 1936 (2007/10/02)
The synthesis of a fused-butyrolactone from D-glucose and its stereospecific alkylation in an off-template position is described, together with an unusual silyl protecting group migration.
Out-of-Ring Claisen Rearrangement are Highly Stereoselective in Pyranoses: Routes to gem-Dialkylated Sugars
Tulshian, Deen Bandhu,Tsang, Raymond,Fraser-Reid, Bert
, p. 2347 - 2355 (2007/10/02)
The Claisen rearrangement has been evaluated as a means for stereoselective creation of functionalized geminal substituents at C-2 and C-3 of hexopyrano systems.C-2 and C-3 keto sugars react with Wittig reagents to give α,β-unsaturated esters, one geometric isomer being obtained in each case.Reduction of the ester and trans vinylation with ethyl vinyl ether leads to allyl vinyl ethers wich are thermolysed in refluxing benzonitrile.The oxy-Cope rearrengement proceeds with complete stereoselectivity, the folding pattern being always from the β-face of the pyranose ring.Thus, the acetaldehyde moiety ends up axially oriented at C-2 and equatorially oriented at C-3.These stereochemical results are not affected by neighboring oxygen substituents nor by the presence or absence of an anomeric alkoxyl functionality.
