Preparation of a fluorous protecting group and its application to the chemoenzymatic synthesis of sialidase inhibitor

2006 ◽  
pp. 3093 ◽  
Author(s):  
Kiyoshi Ikeda ◽  
Hitomi Mori ◽  
Masayuki Sato
Keyword(s):  
Chemoenzymatic Synthesis ◽  
Protecting Group ◽  
Sialidase Inhibitor

A One-Pot Chemoenzymatic Synthesis of (2S,4R)-4-Methylproline Enables the First Total Synthesis of Antiviral Lipopeptide Cavinafungin B

2018 ◽  
Author(s):  
Christian R. Zwick ◽  
Hans Renata
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Complex Molecule ◽  
Molecular Target ◽  
Chemoenzymatic Synthesis ◽  
General Strategy ◽  
One Pot

We report an efficient ten-step synthesis of antiviral natural product cavinafungin B in 37% overall yield. By leveraging a one-pot chemoenzymatic synthesis of (2S,4R)-4-methylproline and oxazolidine-tethered (Rink-Boc-ATG-resin) SPPS methodology, the assembly of our molecular target could be conducted in an efficient manner.This general strategy could prove amenable to the construction of other natural and unnatural linear lipopeptides. The value of incorporating biocatalytic steps in complex molecule synthesis is highlighted by this work.

Short Protecting Group-free Syntheses of CDE Synthon of Racemic Camptothecin

2020 ◽  
Vol 17 (7) ◽  
pp. 588-591
Author(s):  
Pingxuan Shao ◽  
Wei Lu ◽  
Lei Wang
Keyword(s):  
Total Synthesis ◽  
Future Development ◽  
Protecting Group ◽  
Short Route ◽  
The Future ◽  
Tricyclic Ketone

A practical and concise total synthesis of tricyclic ketone 7 (CDE ring), a valuable intermediate for the synthesis of racemic camptothecin and analogs, was described (8 chemical steps and 29% overall yield). The synthesis starts with two inexpensive, readily available materials and is operationally simple to perform. It is worth mentioning that the reported protecting group-free synthesis, with advantages of a short route, would be helpful for the future development of industry-scale syntheses of camptothecin-family alkaloids.

Fluoroquinolone-3-carboxamide Amino Acid Conjugates: Synthesis, Antibacterial Properties And Molecular Modeling Studies

2020 ◽  
Vol 17 (1) ◽  
pp. 71-84
Author(s):  
Riham M. Bokhtia ◽  
Siva S. Panda ◽  
Adel S. Girgis ◽  
Hitesh H. Honkanadavar ◽  
Tarek S. Ibrahim ◽  
...  
Keyword(s):  
Experimental Data ◽  
Antibacterial Activity ◽  
Amino Acid ◽  
Bacterial Infections ◽  
Antibacterial Agents ◽  
Antibacterial Properties ◽  
Computational Studies ◽  
Protecting Group ◽  
Amino Acid Conjugates ◽  
Molecular Modeling Studies

Background: Bacterial infections are considered as one of the major global health threats, so it is very essential to design and develop new antibacterial agents to overcome the drawbacks of existing antibacterial agents. Method: The aim of this work is to synthesize a series of new fluoroquinolone-3-carboxamide amino acid conjugates by molecular hybridization. We utilized benzotriazole chemistry to synthesize the desired hybrid conjugates. Result: All the conjugates were synthesized in good yields, characterized, evaluated for their antibacterial activity. The compounds were screened for their antibacterial activity using methods adapted from the Clinical and Laboratory Standards Institute. Synthesized conjugates were tested for activity against medically relevant pathogens; Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27856) Staphylococcus aureus (ATCC 25923) and Enterococcus faecalis (ATCC 19433). Conclusion: The observed antibacterial experimental data indicates the selectivity of our synthesized conjugates against E.Coli. The protecting group on amino acids decreases the antibacterial activity. The synthesized conjugates are non-toxic to the normal cell lines. The experimental data were supported by computational studies.

Synthesis of (15E)-17β-hydroxy-5α-androstane-3,15-dione 15-[O-(Carboxymethyl)]oxime, New Hapten for Dihydrotestosterone (17β-hydroxy-5α-androstan-3-one)

1997 ◽  
Vol 62 (10) ◽  
pp. 1642-1649 ◽  
Author(s):  
Ivan Černý ◽  
Tereza Slavíková ◽  
Vladimír Pouzar
Keyword(s):  
Hydroxy Group ◽  
Carboxy Group ◽  
Title Compound ◽  
Oxidative Cleavage ◽  
Hydroxy Derivative ◽  
Borohydride Reduction ◽  
Protecting Group ◽  
Free Hydroxy Group

Addition of 4-methoxybenzyl alcohol to 3β-hydroxy-5α-androst-15-en-17-one gave the mixture of isomeric 15-(4-methoxyphenyl)methoxy derivatives from which, after acetylation and chromatography, the major 15β isomer was separated. Borohydride reduction gave 17β-hydroxy derivative which was protected as methoxymethyl ether. Oxidative cleavage of protecting group at position 15 and the subsequent Jones oxidation afforded corresponding 15-ketone. Its oximation with O-(carboxymethyl)hydroxylamine, deacetylation and methylation with diazomethane gave protected O-(carboxymethyl)oxime derivative with free hydroxy group at position 3. Its oxidation afforded dihydrotestosterone derivative and successive deprotection of position 17 and of carboxy group led to final (15E)-17β-hydroxy-5α-androstane-3,15-dione 15-[O-(carboxymethyl)]oxime. The title compound was designed as dihydrotestosterone hapten for heterologous radioimmunoassays.

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