scholarly journals A general approach to 2,2-disubstituted indoxyls: total synthesis of brevianamide A and trigonoliimine C

2021 ◽  
Author(s):  
Fan Xu ◽  
Myles W. Smith
Keyword(s):  
Total Synthesis ◽  
Total Syntheses ◽  
User Friendly ◽  
General User

A general, user-friendly approach to 2,2-disubstituted indoxyls is presented. The method is particularly useful for the preparation of 2,2-dialkylindoxyl products, and is applied to concise total syntheses of brevianamide A and trigonoliimine C.

scholarly journals Xylochemical Synthesis and Biological Evaluation of Shancigusin C and Bletistrin G

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3224
Author(s):  
Leander Geske ◽  
Ulrich Kauhl ◽  
Mohamed E. M. Saeed ◽  
Anja Schüffler ◽  
Eckhard Thines ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Biological Activities ◽  
Biological Evaluation ◽  
Aromatic Substitution ◽  
Substitution Reactions ◽  
Total Syntheses ◽  
Wittig Olefination ◽  
Starting Point ◽  
Perkin Reaction ◽  
Synthesis And Biological Evaluation

The biological activities of shancigusin C (1) and bletistrin G (2), natural products isolated from orchids, are reported along with their first total syntheses. The total synthesis of shancigusin C (1) was conducted by employing the Perkin reaction to forge the central stilbene core, whereas the synthesis of bletistrin G (2) was achieved by the Wittig olefination followed by several regioselective aromatic substitution reactions. Both syntheses were completed by applying only renewable starting materials according to the principles of xylochemistry. The cytotoxic properties of shancigusin C (1) and bletistrin G (2) against tumor cells suggest suitability as a starting point for further structural variation.

Total syntheses and antiproliferative activities of prenostodione and its analogues

2021 ◽  
Author(s):  
Aldahir Ramos Orea ◽  
María Teresa Ramírez-Apan ◽  
Rosa M. Chávez-Santos ◽  
Rodrigo Aguayo-Ortiz ◽  
Clara I Espitia ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Total Synthesis ◽  
Indole Alkaloid ◽  
Total Syntheses ◽  
Antiproliferative Activities

A high-yielding total synthesis of the indole alkaloid prenostodione was completed in 4 steps and 44% overall yield from 1H-indole-3-carboxylic acid. The expedient syntheses of prenostodiones containing distinct substituents at...

scholarly journals Stereoselective total syntheses of (±)-sinularene and (±)-5-epi-sinularene: a general intramolecular Diels–Alder approach to tricyclic sesquiterpenes

1985 ◽  
Vol 63 (4) ◽  
pp. 993-995 ◽  
Author(s):  
Kazimierz Antczak ◽  
John F. Kingston ◽  
Alex G. Fallis
Keyword(s):  
Double Bond ◽  
Methyl Ester ◽  
Total Synthesis ◽  
Ring System ◽  
Diels Alder ◽  
Exocyclic Double Bond ◽  
Total Syntheses ◽  
Methyl Group ◽  
Secondary Hydroxyl ◽  
Selective Hydrogenolysis

Stereoselective total synthesis of (±)-sinularene and (±)-5-epi-sinularene are described. The sequence employs a "blocked" cyclopentadiene in which the cyclopropane unit also serves as a latent methyl group. Thus intramolecular [4 + 2] cycloaddition of the substituted methyl spiro[2.4]hepta-4,6-dien-1-yl)-2-pentenoate 11 affords 5-benzyloxy-6-isopropyl-8-carbomethoxytetracyclo[5.4.01,7.02,4.02,9]undec-10-ene (12) which after selective hydrogenolysis generates the tricyclo[4.4.01,6.02,8]decane (sinularene) ring system. Removal of the secondary hydroxyl function (Ph3P/CCl4/CH3CN; H2/Pd/C), reduction of the methyl ester (LiAlH4), and introduction of the exocyclic double bond (acetate pyrolysis, 550 °C) completes the synthesis of (±)-sinularene in 14 steps from cyclopentadiene. A parallel series of reactions employing the isopropyl epimer of 12 affords (±)-5-epi-sinularene.

Recent Advances in the Total Synthesis of Clavaminols

Synthesis ◽  
2018 ◽  
Vol 50 (23) ◽  
pp. 4569-4576
Author(s):  
Tian Jin ◽  
Lu Zhao ◽  
Zhe-Bin Zheng ◽  
Xiao Liu ◽  
Liang Sun ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Research Groups ◽  
Total Syntheses ◽  
New Class ◽  
Recent Advances ◽  
Molecular Architectures ◽  
Synthetic Approaches ◽  
Long Chain

Clavaminols are a new class of long-chain 2-amino-3-­alkanols that mostly contain 2R,3S-configurations. Owing to their interesting molecular architectures and promising activities, they have ­become popular targets for synthetic organic chemists. In this review, we highlight 12 total syntheses of clavaminols from different research groups during the period 2009 to 2018.1 Introduction2 Synthetic Approaches toward Clavaminols2.1 Total Synthesis by Chemla and Colleagues (2009)2.2 Total Synthesis by Greck and Colleagues (2010)2.3 Total Synthesis by Sutherland and Zaed (2011)2.4 Total Synthesis by Huang and Colleagues (2011)2.5 Total Synthesis by Kotora and Colleagues (2012)2.6 Total Synthesis by Kumar and Colleagues (2013)2.7 Total Synthesis by Prabhavathi Devi and Colleagues (2013 and 2016)2.8 Total Synthesis by Sarabia and Colleagues (2014)2.9 Total Synthesis by Mohapatra and Colleagues (2016)2.10 Total Synthesis by Lu and Colleagues (2016)2.11 Total Synthesis by Jin and Colleagues (2017)2.12 Total Synthesis by Kumar Pandey and Colleagues (2018)3 Conclusion

scholarly journals Total syntheses of all tri-oxygenated 16-phytoprostane classes via a common precursor constructed by oxidative cyclization and alkyl–alkyl coupling reactions as the key steps

2017 ◽  
Vol 15 (44) ◽  
pp. 9408-9414 ◽  
Author(s):  
Jakub Smrček ◽  
Radek Pohl ◽  
Ullrich Jahn
Keyword(s):  
Total Synthesis ◽  
Oxidative Cyclization ◽  
Coupling Reactions ◽  
Total Syntheses ◽  
Common Precursor ◽  
Key Steps

A parallel total synthesis of 16-F1t-, 16-E1-phytoprostanes and a first synthesis of 16-D1t-phytoprostanes based on a common precursor are described.

scholarly journals Oxazolidinones as Chiral Auxiliaries in the Asymmetric 1,4-Conjugate Addition Reaction Applied to the Total Synthesis of Natural Products: A Supplemental Mini-Review

2018 ◽  
Vol 15 (1) ◽  
pp. 3-20 ◽  
Author(s):  
Vahideh Zadsirjan ◽  
Majid M. Heravi
Keyword(s):  
Total Synthesis ◽  
Biological Activities ◽  
Conjugate Addition ◽  
Chiral Auxiliary ◽  
Addition Reactions ◽  
Chiral Auxiliaries ◽  
Complex Molecules ◽  
Total Syntheses ◽  
Naturally Occurring ◽  
Wide Range

Background: The most frequently used chiral auxiliaries, oxazolidinones (Evans' oxazolidinones) have been employed in 1,4-congugate addition reactions to α,β-unsaturated carbonyl compounds. Supplementary to our previous reports in this mini-review, we attempted to underscore the applications of this strategy in a step (steps) in the total synthesis of some naturally occurring compounds exhibiting diverse biological activities. Objective: In this mini-review, we try to underscore the applications of oxazolidinones (Evans’ oxazolidinones) in 1,4-congugate addition reactions to α,β-unsaturated carbonyl in the total synthesis of some naturally occurring compounds exhibiting diverse biological activities. Conclusion: In spite of well-known superiority of asymmetric catalyzed reactions, the use of auxiliarycontrolled reactions are still considered as commanding, vital and sometimes as only tools in the generation of stereogenic centers during the construction of complex molecules and total synthesis of naturally occurring compounds. The commercial availability, or readily accessibility of a wide variety of chiral amino alcohols as starting materials to synthesize a wide range of oxazolidinones is the merits of them. In addition, the ease of removal and subjection to various and diverse stereoselective reactions make oxazolidinones as the ideal and superior chiral auxiliaries. In this regard, they were successfully used in asymmetric 1,4-conjugate addition reactions with high stereoselectivities. The high degree of asymmetric induction can be attributed to the rigid chelation of N-acyloxazolidinones with metal ions, as well as the covering of one face of the system by the bulkiness of 4-substituent. In summary, in this report, the importance of the applications of chiral oxazolidinones as suitable chiral auxiliaries in the stereoselective, 1,4-conjugate addition reactions in asymmetric synthesis and in particular, the total synthesis of naturally occurring compounds and some complex molecules were underscored. Noticeably, in these total syntheses, this chiral auxiliary is controlling the stereochemistry of a newly created stereogenic center as well as preserving the configuration of other chiral centers, which already have been presented in the precursor. General methods have been established for the attachment of the chiral auxiliary as a moiety to the substrate molecule in high to excellent yields. At the end of these reactions, this auxiliary can be easily removed leaving various desired reactive motifs for the next step in multi-step synthesis.

Total synthesis of the potent antifungal agents bengazole C and E

2009 ◽  
Vol 74 (6) ◽  
pp. 887-900 ◽  
Author(s):  
Álvaro Enríquez-García ◽  
Steven V. Ley
Keyword(s):  
Natural Products ◽  
Antifungal Activity ◽  
Total Synthesis ◽  
Marine Natural Products ◽  
Antifungal Agents ◽  
Nitrile Oxide ◽  
Total Syntheses ◽  
Unique Structure

The bengazoles are marine natural products with unique structure, containing two oxazole rings flanking a single carbon. They show very potent antifungal activity. The total syntheses of bengazole C and E are described following a convergent route which involves diastereoselective cycloaddition of an appropriately substituted nitrile oxide with a butane-1,2-diacetal-protected alkenediol as the key step.

scholarly journals Bioinspired Oxidative Cyclization of the Geissoschizine Skeleton for the Enantioselective Total Synthesis of Mavacuran Alkaloids

2019 ◽  
Author(s):  
Maxime Jarret ◽  
Victor Turpin ◽  
Aurélien Tap ◽  
Jean-Francois Gallard ◽  
Cyrille Kouklovsky ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Oxidative Coupling ◽  
Indole Alkaloids ◽  
Oxidative Cyclization ◽  
Total Syntheses ◽  
Enantioselective Total Synthesis ◽  
Biosynthetic Precursor ◽  
Monoterpene Indole Alkaloids ◽  
Coupling Approach

We report the enantioselective total syntheses of mavacurans alkaloids, (+)-taberdivarine H, (+)-16-hydoxymethyl-pleiocarpamine, (+)-16-epi-pleiocarpamine, and their postulated biosynthetic precursor 16-formyl-pleiocarpamine. This family of monoterpene indole alkaloids is a target of choice since some of its members are subunits of intricate bisindole alkaloids such as bipleiophylline. Inspired by the biosynthetic hypothesis, we explored an oxidative coupling approach from the geissoschizine framework to form the N1-C16 bond. Quaternization of the aliphatic nitrogen was key to achieve the oxidative coupling induced by KHMDS/I<sub>2 </sub>since<sub> </sub>it hides the nucleophilicity of the aliphatic nitrogen and locks the required cis conformation.

scholarly journals Total Syntheses of Pladienolide-Derived Spliceosome Modulators

Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 5938
Author(s):  
Jaehoon Sim ◽  
Eunbin Jang ◽  
Hyun Jin Kim ◽  
Hongjun Jeon
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Structural Features ◽  
Synthetic Approach ◽  
Synthetic Analog ◽  
Phase I Clinical Trials ◽  
Total Syntheses ◽  
Naturally Occurring ◽  
Anti Cancer ◽  
Synthetic Approaches

Pladienolides, an emerging class of naturally occurring spliceosome modulators, exhibit interesting structural features, such as highly substituted 12-membered macrocycles and epoxide-containing diene side chains. The potential of pladienolides as anti-cancer agents is confirmed by H3B-8800, a synthetic analog of this natural product class, which is currently under Phase I clinical trials. Since its isolation in 2004 and the first total synthesis in 2007, a dozen total syntheses and synthetic approaches toward the pladienolide class have been reported to date. This review focuses on the eight completed total syntheses of naturally occurring pladienolides or their synthetic analogs, in addition to a synthetic approach to the main framework of the natural product.

Aryne-based strategy in the total synthesis of naturally occurring polycyclic compounds

2018 ◽  
Vol 47 (21) ◽  
pp. 8030-8056 ◽  
Author(s):  
Hiroshi Takikawa ◽  
Arata Nishii ◽  
Takahiro Sakai ◽  
Keisuke Suzuki
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Polycyclic Compounds ◽  
Total Syntheses ◽  
Naturally Occurring

This review has outlined the strategies and tactics of using arynes in the total syntheses of polycyclic natural products.

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