Synthetic Study on Carthamin, Part 4. Improved Synthesis of a C-Glycosyl Quinochalcone by Installation of a Side Chain through Regioselective De-O-methylation and Acyl Rearrangement

Synlett ◽  
2021 ◽  
Author(s):  
Ken Ohmori ◽  
Keisuke Suzuki ◽  
Seiya Matsuoka ◽  
Kohei Azami ◽  
Yusuke Fujiki ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Side Chain ◽  
Red Pigment

AbstractWe report an improved synthesis of a C-Glycosyl quinochalcone that is a key intermediate in our total synthesis of carthamin, a natural red pigment of traditional heritage. The C-glycosyl quinochalcone is prepared by regioselective de-O-methylation of a C-glycosyl bromodienone, and installation of a p-coumaroyl side chain through an O→C acyl rearrangement.

ChemInform Abstract: Total Synthesis of a New 7-Deoxyidarubicinone Derivative Through the Functionalization of an A-Ring Side Chain.

ChemInform ◽  
2000 ◽  
Vol 31 (49) ◽  
pp. no-no
Author(s):  
Young S. Rho ◽  
Hyun Kyoung Ko ◽  
Wan-Joong Kim ◽  
Dong Jin Yoo ◽  
Heun Soo Kang
Keyword(s):  
Total Synthesis ◽  
Side Chain

Zur Totalsynthese des Human-Big-Gastrins I und seines 32-Leucin-Analogons (Vorläufige Mitteilung) / Total Synthesis of Human Big Gastrin I and the 32-Leucine Analogue (Preliminary Communication)

1977 ◽  
Vol 32 (7-8) ◽  
pp. 495-506 ◽  
Author(s):  
E. Wünsch ◽  
G. Wendlberger ◽  
A. Hallett ◽  
E. Jaeger ◽  
S. Knof ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Building Blocks ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Protecting Groups ◽  
Side Chain ◽  
Tertiary Alcohols ◽  
Synthetic Product ◽  
Preliminary Communication ◽  
Final Purification

A new total synthesis of the tetratriacontapeptide amide corresponding to the proposed primary structure of human big gastrin I is described. The synthetic route was based on the preparation of six suitably protected fragments, related to sequence 28 - 34, 23 - 27, 21 - 22, 15-20, 9 - 14, and 1 - 8, to be used as building blocks for the total synthesis. The protecting groups were selected according to the Schwyzer-Wünsch strategy of maximum side chain protection based on tertiary alcohols, also for the imidazol function of histidine. Subsequent assembly of the six fragments by three different pathways using the highly efficient Wünsch-Weygand condensation procedure to ensure minimum racemization, followed by deprotection of the synthetic products via exposure to trifluoroacetic acid and final purification by ion-exchange chromatography on DEAE-Sephadex A-25 and partition chromatography on Sephadex G-25, led to human big gastrin I, homogeneous within the limits of the analytical methods used. The biological activity of the synthetic product proved to be 50 percent higher than that of human little gastrin I. The 32-leucine analogue of human big gastrin I was prepared in the same way.

Synthesis of Dichotomin A: Use of a Penicillamine-Derived Pseudoproline to Furnish Native Valine Residues

2015 ◽  
Vol 68 (4) ◽  
pp. 627 ◽  
Author(s):  
Michelle S. Y. Wong ◽  
Deni Taleski ◽  
Katrina A. Jolliffe
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Side Chain ◽  
Linear Peptide ◽  
Cyclic Hexapeptide ◽  
Peptide Precursors ◽  
Head To Tail Cyclization

The total synthesis of cyclic hexapeptide dichotomin A from linear peptide precursors containing penicillamine-derived pseudoproline residues is reported. The incorporation of a pseudoproline residue led to a faster reaction and higher head-to-tail cyclization yields in comparison to linear precursors containing the native valine residue. However, deprotection of the pseudoproline resulted in significant amounts of a by-product in which a threonine side chain had undergone dehydration, resulting in a low overall yield of the natural product.

scholarly journals Total Synthesis of Caprazamycin A: Practical and Scalable Synthesis of syn-β-Hydroxyamino Acids and Introduction of a Fatty Acid Side Chain to 1,4-Diazepanone

2019 ◽  
Vol 141 (21) ◽  
pp. 8527-8540 ◽  
Author(s):  
Hugh Nakamura ◽  
Chihiro Tsukano ◽  
Takuma Yoshida ◽  
Motohiro Yasui ◽  
Shinsuke Yokouchi ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Total Synthesis ◽  
Side Chain ◽  
Hydroxyamino Acids ◽  
Scalable Synthesis

scholarly journals Regioselective side-chain amination of 2-alkyl azacycles by radical translocation: total synthesis of tetraponerine T8

2021 ◽  
Author(s):  
Samuel D. Griggs ◽  
Alejandro Martin-Roncero ◽  
Adam Nelson ◽  
Stephen P. Marsden
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Side Chain

Radical translocation facilitates the regioselective γ-amination of 2-alkyl-substituted azacycles, leading to 1,3-diamines including the alkaloidal natural product tetraponerine T8.

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