scholarly journals Unified Strategy to Prostaglandins: Chemoenzymatic Total Synthesis of Cloprostenol, Bimatoprost, PGF2α, Fluprostenol, and Travoprost Guided by Biocatalytic Retrosynthesis

2021 ◽  
Author(s):  
Kejie Zhu ◽  
Meifen Jiang ◽  
Baijun Ye ◽  
Guotai Zhang ◽  
Weijian Li ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Stereoselective Synthesis ◽  
Secondary Alcohol ◽  
Complex Molecules ◽  
Chemical Structures ◽  
12 Steps ◽  
Diastereoselective Reduction ◽  
Stereoselective Oxidation ◽  
First Time ◽  
Unique Chemical

Abstract Development of efficient and stereoselective synthesis of prostaglandins (PGs) is of utmost importance, owing to their valuable medicinal applications and unique chemical structures. We report here a unified synthesis of PGs cloprostenol, bimatoprost, PGF2α, fluprostenol, and travoprost from the readily available dichloro-containing bicyclic ketone 6a guided by biocatalytic retrosynthesis, in 11-12 steps with 2.9-6.5% overall yields. A Baeyer-Villiger monooxygenase (BVMO)-catalyzed stereoselective oxidation of 6a (99% ee), and a ketoreductase (KRED)-catalyzed diastereoselective reduction of enones 12 (87 : 13 to 99 : 1 dr) were utilized in combination for the first time to set the critical stereochemical configurations under mild conditions. Another key transformation was the copper (II)-catalyzed regioselective p-phenylbenzoylation of the secondary alcohol of diol 10 (3.8 : 1 rr). This study not only provides an alternative route to the highly stereoselective synthesis of PGs, but also showcases the usefulness and great potential of biocatalysis in construction of complex molecules.

scholarly journals Unified Strategy to Prostaglandins: Chemoenzymatic Total Synthesis of Cloprostenol, Bimatoprost, PGF2, Fluprostenol, and Travoprost Guided by Biocatalytic Retrosynthesis

2021 ◽  
Author(s):  
Kejie Zhu ◽  
Meifen Jiang ◽  
Baijun Ye ◽  
Guo-Tai Zhang ◽  
Weijian Li ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Stereoselective Synthesis ◽  
Chemical Structures ◽  
Unique Chemical

Development of efficient and stereoselective synthesis of prostaglandins (PGs) is of utmost importance, owing to their valuable medicinal applications and unique chemical structures. We report here a unified synthesis of...

Towards the Total Synthesis of Schisandrene: Stereoselective Synthesis of the Dibenzocyclooctadiene Lignan Core

Synlett ◽  
2018 ◽  
Vol 29 (07) ◽  
pp. 908-911 ◽  
Author(s):  
K. Babu ◽  
Arramshetti Venkanna ◽  
Borra Poornima ◽  
Bandi Siva ◽  
B. Babu
Keyword(s):  
Total Synthesis ◽  
Stereoselective Synthesis ◽  
Asymmetric Reduction ◽  
Cross Coupling ◽  
Membered Ring ◽  
Stille Reaction ◽  
Reaction Sequence ◽  
Ring Closing Metathesis ◽  
Synthetic Strategy ◽  
First Time

A stereoselective synthesis of the dibenzocyclooctadiene ­lignan core of the natural product schisandrene is described. Starting from readily available gallic acid, the synthetic strategy involves Suzuki–Miyaura cross-coupling, Stille reaction, and ring-closing metathesis (RCM) in the reaction sequence. The required asymmetric center at C-7′ was established by an asymmetric reduction of a keto compound using the Corey–Bakshi–Shibata (CBS) catalyst. In our approach, the eight-membered ring was achieved by RCM for the first time.

First Total Synthesis of Pamamycin-621D

2018 ◽  
Vol 15 (1) ◽  
pp. 105-109 ◽  
Author(s):  
Hassan Norouzi-Arasi ◽  
Xavier J. Salom-Roig ◽  
Steve Lanners ◽  
Gilles Hanquet
Keyword(s):  
Total Synthesis ◽  
Optical Rotation ◽  
Large Family ◽  
Synthetic Approach ◽  
General Strategy ◽  
Structural Assignment ◽  
12 Steps ◽  
Aldol Addition ◽  
Additional Support ◽  
First Time

Aim and Objective: The objective of our work was to synthesize and fully characterize Pamamycin- 621D, one of the less abundant members of a large family of macrodiolides with antimycobacterial properties, which had never been synthesized before. Furthermore, we also wished to improve our general strategy by using a new unsaturated precursor. Materials and Method: A new unsaturated ethylketone precursor was prepared using alkene cross metathesis, and a convergent and flexible strategy based on a key diastereoselective aldol addition was implemented to afford pamamycin-621D in 12 steps from that precursor. Results: Pamamycin-621D has been obtained and fully characterized for the first time. The structure of pamamycin-621D was confirmed by HRMS and comparison of 1H-NMR spectra with the natural pamamycin- 621D. Both optical rotation and 13C-NMR had not been published previously due to lack of material, and the latter are reported here for the first time. Given the scarce characterization available previously, our synthesis also gives additional support to the initial structural assignment of pamamycin-621D. A significant improvement of the key aldol addition via the use of a new unsaturated precursor is also reported. Conclusion: The work described above constitutes the first total synthesis of pamamycin-621D and has enabled us to fully characterize this scarcely available natural product. More importantly, this work highlights the fact that our synthetic approach provides ready access to various members of the pamamycin family, allowing possible studies on structure-activity relationships and mode of action of even the least abundant of these natural products. The synthesis of other pamamycin congeners and biological investigations will be published in due course.

scholarly journals Application of asymmetric Sharpless aminohydroxylation in total synthesis of natural products and some synthetic complex bio-active molecules

RSC Advances ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 6634-6659 ◽  
Author(s):  
Majid M. Heravi ◽  
Tahmineh Baie Lashaki ◽  
Bahareh Fattahi ◽  
Vahideh Zadsirjan
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Stereoselective Synthesis ◽  
Biological Activities ◽  
Amino Alcohols ◽  
Complex Molecules

This work shows applications of Asymmetric Sharpless Aminohydroxylation (ASAH) in the stereoselective synthesis of vicinal amino alcohols as important intermediates in the total synthesis of complex molecules and natural products with significant biological activities.

The Total Synthesis of Rhabdastrellic Acid A

2018 ◽  
Author(s):  
Yaroslav Boyko ◽  
Christopher Huck ◽  
David Sarlah
Keyword(s):  
Total Synthesis ◽  
Late Stage ◽  
Cross Coupling ◽  
Side Chains ◽  
General Strategy ◽  
Modular Approach ◽  
Linear Sequence ◽  
Generating Sequence ◽  
First Time

<div>The first total synthesis of rhabdastrellic acid A, a highly cytotoxic isomalabaricane triterpenoid, has been accomplished in a linear sequence of 14 steps from commercial geranylacetone. The prominently strained <i>trans-syn-trans</i>-perhydrobenz[<i>e</i>]indene core characteristic of the isomalabaricanes is efficiently accessed in a selective manner for the first time through a rapid, complexity-generating sequence incorporating a reductive radical polyene cyclization, an unprecedented oxidative Rautenstrauch cycloisomerization, and umpolung 𝛼-substitution of a <i>p</i>-toluenesulfonylhydrazone with in situ reductive transposition. A late-stage cross-coupling in concert with a modular approach to polyunsaturated side chains renders this a general strategy for the synthesis of numerous family members of these synthetically challenging and hitherto inaccessible marine triterpenoids.</div>

Chitosan in Biomedical Engineering: A Critical Review

2019 ◽  
Vol 14 (2) ◽  
pp. 93-116 ◽  
Author(s):  
Shabnam Mohebbi ◽  
Mojtaba Nasiri Nezhad ◽  
Payam Zarrintaj ◽  
Seyed Hassan Jafari ◽  
Saman Seyed Gholizadeh ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Biomedical Engineering ◽  
Biological Properties ◽  
Advanced Materials ◽  
Comprehensive Overview ◽  
Chemical Structures ◽  
Bio Imaging ◽  
Significant Attention ◽  
Unique Chemical

Biomedical engineering seeks to enhance the quality of life by developing advanced materials and technologies. Chitosan-based biomaterials have attracted significant attention because of having unique chemical structures with desired biocompatibility and biodegradability, which play different roles in membranes, sponges and scaffolds, along with promising biological properties such as biocompatibility, biodegradability and non-toxicity. Therefore, chitosan derivatives have been widely used in a vast variety of uses, chiefly pharmaceuticals and biomedical engineering. It is attempted here to draw a comprehensive overview of chitosan emerging applications in medicine, tissue engineering, drug delivery, gene therapy, cancer therapy, ophthalmology, dentistry, bio-imaging, bio-sensing and diagnosis. The use of Stem Cells (SCs) has given an interesting feature to the use of chitosan so that regenerative medicine and therapeutic methods have benefited from chitosan-based platforms. Plenty of the most recent discussions with stimulating ideas in this field are covered that could hopefully serve as hints for more developed works in biomedical engineering.

Concise Total Synthesis of Curvulone B

Synlett ◽  
2020 ◽  
Author(s):  
Debendra K. Mohapatra ◽  
Shivalal Banoth ◽  
Utkal Mani Choudhury ◽  
Kanakaraju Marumudi ◽  
Ajit C. Kunwar
Keyword(s):  
Total Synthesis ◽  
Stereoselective Synthesis ◽  
Ring System ◽  
Bond Forming ◽  
Cross Metathesis ◽  
Bond Forming Reactions ◽  
Key Steps

AbstractA concise and convergent stereoselective synthesis of curvulone B is described. The synthesis utilized a tandem isomerization followed by C–O and C–C bond-forming reactions following Mukaiyama-type aldol conditions for the construction of the trans-2,6-disubstituted dihydropyran ring system as the key steps. Other important features of this synthesis are a cross-metathesis, epimerization, and Friedel–Crafts acylation.

Stereoselective synthesis of O-tosyl azabicyclic derivatives via aza Prins reaction of endocyclic N-acyliminium ions: application to the total synthesis of (±)-epi-indolizidine 167B and 209D

2014 ◽  
Vol 12 (36) ◽  
pp. 7026-7035 ◽  
Author(s):  
Anil K. Saikia ◽  
Kiran Indukuri ◽  
Jagadish Das
Keyword(s):  
Total Synthesis ◽  
Stereoselective Synthesis ◽  
Cyclization Reaction ◽  
Diastereoselective Synthesis ◽  
Prins Reaction ◽  
Prins Cyclization ◽  
Acyliminium Ions

A diastereoselective synthesis of 4-O-tosyl piperidine containing azabicyclic derivatives has been established via Prins cyclization reaction. This protocol has been applied for the total synthesis of (±)-epi-indolizidine 167B and 209D.

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