scholarly journals Total Synthesis of Natural Disaccharide Sambubiose

2020 ◽  
Vol 13 (8) ◽  
pp. 198
Author(s):  
Simone Lucarini ◽  
Maria Gessica Ciulla ◽  
Paola Mestichelli ◽  
Andrea Duranti
Keyword(s):  
Total Synthesis ◽  
Synthetic Method ◽  
Target Compound ◽  
Single Isomer

A practical and robust synthetic method to obtain the natural disaccharide sambubiose (2-O-β-D-xylopyranosyl-D-glucopyranose) is reported, exploring the key step in the synthesis, i.e., stereoselective O-glycosylation. Specifically, the best combinations of glycoside donors and acceptors were identified, stereospecific control of the reaction was achieved by screening several catalysts and protection/deprotection steps were evaluated and improved. The best result was obtained by coupling allyl 3,5,6-tri-O-benzyl-β-D-glucofuranoside with 2,3,4-tri-O-acetyl-D-xylopiranosyl-α-trichloro acetimidate in the presence of trimethylsilyl triflate as a catalyst giving the corresponding protected target compound as a correct single isomer. The latter was transformed accordingly into the desired final product by deprotection steps (deallylation, deacetylation, and debenzylation). Sambubiose was synthesized into a satisfactory and higher overall yield than previously reported and was also characterized.

Total Synthesis of the Antitumor Depsipeptide FE399 and its S-Benzyl Derivative: A Macrolactamization Approach

2020 ◽  
Author(s):  
Takayuki Tonoi ◽  
Miyuki Ikeda ◽  
Teruyuki Sato ◽  
Ryo Kawahara ◽  
Takatsugu Murata ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Total Synthesis ◽  
Natural Product ◽  
Condensation Reaction ◽  
Practical Method ◽  
Equilibrium Mixture ◽  
Conformational Isomers ◽  
Single Isomer

<div>An efficient and practical method for the synthesis of (9R,14R,17R)-FE399, a novel antitumor bicyclic depsipeptide, was developed. A 2-methyl-6-nitrobenzoic anhydride (MNBA)-mediated dehydration condensation reaction was effectively employed for the formation of the 16-membered macrocyclic depsipeptide moiety of FE399. FE399 was found to exist as an inseparable equilibrium mixture of conformational isomers; the mixture was quantitatively transformed into the corresponding S-benzyl product and isolated as a single isomer. Thus, we could confirm that the molecular structure of FE399 obtained by this method is identical to that of the natural product.</div>

First Total Synthesis of a Fluorinated Calystegin

2010 ◽  
Vol 65 (4) ◽  
pp. 445-451 ◽  
Author(s):  
René Csuk ◽  
Erik Prell ◽  
Stefan Reißmann ◽  
Claudia Korb
Keyword(s):  
Total Synthesis ◽  
Ring Opening ◽  
Competitive Inhibitor ◽  
Ring Closure ◽  
Target Compound ◽  
Metathesis Reaction ◽  
Grubbs Catalyst ◽  
Ring Opening Reaction ◽  
Ultrasound Assisted ◽  
Key Steps

A straightforward chiral pool synthesis for the first fluorinated calystegin is described. Key steps of this synthesis include an ultrasound-assisted Zn-mediated tandem ring opening reaction followed by a Grubbs’ catalyst-mediated ring closure metathesis reaction. The target compound is a selective and competitive inhibitor for a β -glycosidase.

Chemoenzymatic Formal Total Synthesis of Pancratistatin from Narciclasine-Type Compounds via Myers Transposition: Model Study for a Short Conversion of Narciclasine to Pancratistatin

Synlett ◽  
2017 ◽  
Vol 28 (20) ◽  
pp. 2896-2900 ◽  
Author(s):  
Ringaile Lapinskaite ◽  
Mukund Ghavre ◽  
Chelsea Rintelmann ◽  
Korey Bedard ◽  
Helen Dela Paz ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Recombinant Strain ◽  
Optical Purity ◽  
Allylic Alcohol ◽  
Formal Synthesis ◽  
Toluene Dioxygenase ◽  
Single Isomer ◽  
Model Study ◽  
New Compounds ◽  
Subsequent Opening

A formal total synthesis of pancratistatin was accomplished by conversion of advanced intermediates, used in the synthesis of narciclasine, to pancratistatin precursors via Myers’ reductive transposition as the key strategic step. The synthesis began with the whole cell fermentation of m-dibromobenzene with JM109(pDTG601a), a recombinant strain that over-expresses toluene dioxygenase, which provided the corresponding cis-dihydrodiol 16 as a single isomer with complete optical purity. The key reductive transposition of the allylic alcohol 8a to olefin 9a allowed for further installation of the C-1/C-2 trans-diol, ­required for the pancratistatin scaffold, through the introduction of a cyclic sulfate and its subsequent opening. The formal synthesis of pancratistatin was accomplished in 14 steps (12 operations) from commercially available m-dibromobenzene. Experimental and spectral data are provided for all new compounds.

scholarly journals Total Synthesis of the Reported Structure of Cahuitamycin A

2020 ◽  
Author(s):  
Justin Shapiro ◽  
Savannah Post ◽  
William Wuest
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Natural Product ◽  
Twelve Step ◽  
Target Compound ◽  
New Family ◽  
Iron Trafficking ◽  
Linear Sequence ◽  
Alternative Structure ◽  
Synthetic Target

In a 2016 screen of natural product extracts a new family of natural products, the cahuitamycins, was discovered and found to inhibit the formation of biofilms in the human pathogen <i>Acinetobacter baumannii</i>. The molecules contain an unusual piperazate residue that raises structure/function and biosynthesis questions and resemble iron-trafficking virulence factors from <i>A. baumannii</i>, suggesting a connection between metal homeostasis and biofilm-mediated pathogenicity. Here we disclose the first total synthesis of the reported structure of cahuitamycin A in a twelve-step longest linear sequence and 18% overall yield. Comparison of spectral data of the authentic natural product and synthetic target compound demonstrate that the reported structure is distinct from the isolated metabolite. Herein, we propose an alternative structure to reconcile our findings with the isolation report, setting the stage for future synthetic and biochemical investigations of an important class of natural products.

Synthesis of plantamajoside, a bioactive dihydroxyphenylethyl glycoside from Plantago major L.

Holzforschung ◽  
2006 ◽  
Vol 60 (5) ◽  
pp. 492-497 ◽  
Author(s):  
Toshinari Kawada ◽  
Yuko Yoneda ◽  
Ryuji Asano ◽  
Ippei Kan-no ◽  
Walther Schmid
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Total Synthesis ◽  
Caffeic Acid ◽  
Spectral Data ◽  
Natural Compound ◽  
Plantago Major ◽  
Target Compound ◽  
Sugar Esters ◽  
Nuclear Magnetic

Abstract The first total synthesis of plantamajoside (1), 2-(3′,4′-dihydroxylphenyl)ethyl-4-O-caffeoyl-3-O-(β-D-glucopyranosyl)-β-D-glucopyranoside, which is one of the dihydroxyphenylethyl glycosides (caffeic acid sugar esters), is described. Key intermediate 2, 2-[3′,4′-bis(O-benzyl)phenyl]ethyl 2,6-di-O-acetyl-4-O-[3′,4′-bis(O-benzyl)caffeoyl]-β-D-glucopyranoside was glycosylated with trichloroacetoimidoyl 2,3,4,6-tetra-O-acetyl-α-D-glycopyranoside (3) to afford plantamajoside derivative 4a, 2-[3′,4′-bis(O-benzyl)phenyl]ethyl 2,6-di-O-acetyl-4-O-[3′,4′-bis(O-benzyl)caffeoyl]-3-O-(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl)-β-D-glucopyranoside, in 39% yield. Plantamajoside derivative 4a was successfully converted into the target compound, plantamajoside (1), through a series of de-protective procedures. 1H- and 13C nuclear magnetic resonance (NMR) spectral data of the synthesized plantamajoside (1) were identical to those of the natural compound.

A simple synthetic method for chiral 1,2-epoxides and the total synthesis of a chiral pheromone epoxide

2000 ◽  
pp. 53-57 ◽  
Author(s):  
Zhi-Bo Zhang ◽  
Zhi-Min Wang ◽  
Yu-Xiu Wang ◽  
Huan-Quan Liu ◽  
Gui-Xin Lei ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Synthetic Method ◽  
Chiral Pheromone

Total synthesis of (+)-pederine. A simple synthetic method for N-(1-methoxyalkyl)amides

1982 ◽  
Vol 23 (39) ◽  
pp. 4043-4046 ◽  
Author(s):  
Fuyuhiko Matsuda ◽  
Mitsutoshi Yanagiya ◽  
Takeshi Matsumoto
Keyword(s):  
Total Synthesis ◽  
Synthetic Method

Heterocycle synthesis via radical reactions

2008 ◽  
Vol 80 (4) ◽  
pp. 717-726 ◽  
Author(s):  
Takeaki Naito
Keyword(s):  
Total Synthesis ◽  
Heterocyclic Compounds ◽  
Alkyl Radical ◽  
Radical Addition ◽  
Synthetic Method ◽  
Asymmetric Total Synthesis ◽  
Heterocycle Synthesis ◽  
Leaving Group ◽  
Martinellic Acid ◽  
Type Radical

A novel synthetic method for the preparation of nitrogen-containing heterocycles via the route involving domino-type radical addition/cyclization reaction of oxime ethers is described. Alkyl radical addition/cyclization of oxime ethers carrying an appropriate leaving group proceeded smoothly to form the alkylated nitrogen-containing heterocyclic compounds. Additionally, tin-mediated radical addition/cyclization/elimination (RACE) reaction of oxime ethers is newly found and successfully applied to an asymmetric total synthesis of (-)-martinellic acid.

Total synthesis of (+)-thromboxane B2 from D-glucose. A detailed account

1981 ◽  
Vol 59 (5) ◽  
pp. 870-877 ◽  
Author(s):  
Stephen Hanessian ◽  
Pierre Lavallee
Keyword(s):  
Total Synthesis ◽  
Thromboxane B2 ◽  
Detailed Account ◽  
Target Compound ◽  
Type Symmetry

The total synthesis of thromboxane B2 from D-glucose is described, based on the recognition of hidden carbohydrate-type symmetry in the molecule. Methyl 2-deoxy-α-D-ribo-hexopyranoside was prepared from D-glucose and manipulated in such a way as to introduce C-branching at C-4 in a stereocontrolled manner. This crucial intermediate was then transformed into the target compound by adaptations of established methodology in the field.

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