scholarly journals Prins cyclization-mediated stereoselective synthesis of tetrahydropyrans and dihydropyrans: an inspection of twenty years

2021 ◽  
Vol 17 ◽  
pp. 932-963
Author(s):  
Asha Budakoti ◽  
Pradip Kumar Mondal ◽  
Prachi Verma ◽  
Jagadish Khamrai
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Stereoselective Synthesis ◽  
Building Blocks ◽  
Active Pharmaceutical Ingredients ◽  
Prins Reaction ◽  
Prins Cyclization ◽  
Pharmaceutical Ingredients ◽  
New Strategies ◽  
Made In

Functionalized tetrahydropyran (THP) rings are important building blocks and ubiquitous scaffolds in many natural products and active pharmaceutical ingredients (API). Among various established methods, the Prins reaction has emerged as a powerful technique in the stereoselective synthesis of the tetrahydropyran skeleton with various substituents, and the strategy has further been successfully applied in the total synthesis of bioactive macrocycles and related natural products. In this context, hundreds of valuable contributions have already been made in this area, and the present review is intended to provide the systematic assortment of diverse Prins cyclization strategies, covering the literature reports of the last twenty years (from 2000 to 2019), with an aim to give an overview on exciting advancements in this area and designing new strategies for the total synthesis of related natural products.

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.

scholarly journals Non-Enzymatic Desymmetrization Reactions in Aqueous Media

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 720
Author(s):  
Satomi Niwayama
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Functional Groups ◽  
Organic Compounds ◽  
Recent Progress ◽  
Aqueous Media ◽  
Building Blocks ◽  
Organic Reactions ◽  
Environmentally Benign ◽  
Enzymatic Desymmetrization

Symmetric organic compounds are generally obtained inexpensively, and therefore they can be attractive building blocks for the total synthesis of various pharmaceuticals and natural products. The drawback is that discriminating the identical functional groups in the symmetric compounds is difficult. Water is the most environmentally benign and inexpensive solvent. However, successful organic reactions in water are rather limited due to the hydrophobicity of organic compounds in general. Therefore, desymmetrization reactions in aqueous media are expected to offer versatile strategies for the synthesis of a variety of significant organic compounds. This review focuses on the recent progress of desymmetrization reactions of symmetric organic compounds in aqueous media without utilizing enzymes.

Recent results toward the stereoselective synthesis of biologically active natural products

2007 ◽  
Vol 79 (2) ◽  
pp. 163-172 ◽  
Author(s):  
Luiz C. Dias ◽  
Luciana G. de Oliveira ◽  
Paulo R. R. Meira
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Cell Cultures ◽  
Stereoselective Synthesis ◽  
Animal Cell ◽  
Biologically Active ◽  
Asymmetric Total Synthesis ◽  
Callystatin A ◽  
Animal Cell Cultures ◽  
Active Natural

This paper describes the convergent and stereocontrolled asymmetric total synthesis of (+)-crocacins C and D, potent inhibitors of animal cell cultures and several yeasts and fungi, and (-)-callystatin A, a potent antitumor polyketide.

scholarly journals Regio- and Stereoselective Synthesis of Acetallic Tetrahydropyrans as Building Blocks for Natural Products Preparation, via a Tandem [4+3]-Cycloaddition/Ozonolysis Process

2016 ◽  
Vol 2016 (27) ◽  
pp. 4674-4695 ◽  
Author(s):  
Ángel M. Montaña ◽  
Albert Corominas ◽  
Juan F. Chesa ◽  
Francisca García ◽  
Mercè Font-Bardia
Keyword(s):  
Natural Products ◽  
Stereoselective Synthesis ◽  
Building Blocks

Alkynyl Prins and Alkynyl Aza-Prins Annulations: Scope and Synthetic Applications

Synthesis ◽  
2020 ◽  
Vol 52 (14) ◽  
pp. 1991-2007 ◽  
Author(s):  
Alison J. Frontier ◽  
Shukree Abdul-Rashed ◽  
Connor Holt
Keyword(s):  
Natural Products ◽  
Small Molecules ◽  
Natural Product ◽  
Natural Product Synthesis ◽  
Pericyclic Reactions ◽  
Prins Reaction ◽  
Prins Cyclization ◽  
Synthetic Utility ◽  
Cascade Processes ◽  
Saturated Heterocycles

This review focuses on alkynyl Prins and alkynyl aza-Prins cyclization­ processes, which involve intramolecular coupling of an alkyne with either an oxocarbenium or iminium electrophile. The oxocarbenium or iminium species can be generated through condensation- or elimination-type processes, to achieve an overall bimolecular annulation that enables the synthesis of both oxygen- and nitrogen-containing­ saturated heterocycles with different ring sizes and substitution patterns. Also discussed are cascade processes in which alkynyl Prins heterocyclic adducts react to trigger subsequent pericyclic reactions, including [4+2] cycloadditions and Nazarov electrocyclizations, to rapidly construct complex small molecules. Finally, examples of the use of alkynyl Prins and alkynyl aza-Prins reactions in the synthesis of natural products are described. The review covers the literature through the end of 2019.1 Introduction1.1 Alkyne-Carbonyl Coupling Pathways1.2 Coupling/Cyclization Cascades Using the Alkynyl Prins Reaction2 Alkynyl Prins Annulation (Oxocarbenium Electrophiles)2.1 Early Work2.2 Halide as Terminal Nucleophile2.3 Oxygen as Terminal Nucleophile2.4 Arene as Terminal Nucleophile (Intermolecular)2.5 Arene Terminal Nucleophile (Intramolecular)2.6 Cyclizations Terminated by Elimination3 Synthetic Utility of Alkynyl Prins Annulation3.1 Alkynyl Prins-Mediated Synthesis of Dienes for a [4+2] Cyclo­- addition­-Oxidation Sequence3.2 Alkynyl Prins Cyclization Adducts as Nazarov Cyclization Precursors3.3 Alkynyl Prins Cyclization in Natural Product Synthesis4 Alkynyl Aza-Prins Annulation4.1 Iminium Electrophiles4.2 Activated Iminium Electrophiles5 Alkynyl Aza-Prins Cyclizations in Natural Product Synthesis6 Summary and Outlook

Biomimetic approach toward the stereoselective synthesis of acetogenins

2003 ◽  
Vol 75 (2-3) ◽  
pp. 259-264 ◽  
Author(s):  
R. V. A. Orru ◽  
Bas Groenendaal ◽  
J. van Heyst ◽  
Mark Hunting ◽  
C. Wesseling ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Broad Spectrum ◽  
Stereoselective Synthesis ◽  
Biological Activities ◽  
Building Blocks ◽  
Hydrocarbon Chain ◽  
Tropical Trees ◽  
Asymmetric Total Synthesis ◽  
Biomimetic Approach

Acetogenins isolated from the Annonaceae family of tropical trees have drawn considerable attention owing to their broad spectrum of biological activities. They are structurally characterized by the presence of one to three tetrahydrofuran rings in the center of a long (partly hydroxylated) hydrocarbon chain that ends in a (functionalized) butenolide moiety. Here we describe some of our results toward the first asymmetric total synthesis of cis-gigantrionenin, a principal acetogenin. In this approach, an enzyme-catalyzed epoxide hydrolysis and an enzyme-triggered double cyclization are crucial and give stereoselective access to essential chiral building blocks.

Dimethylformamide Acetals and Bredereck’s Reagent as Building Blocks in Natural Products Total Synthesis

2020 ◽  
Vol 17 (1) ◽  
pp. 47-66
Author(s):  
Franz Bracher
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Alkylating Agents ◽  
Building Blocks ◽  
Methyl Groups ◽  
Open Chain ◽  
Enol Ethers ◽  
Condensation Products ◽  
Condensation Reactions

Dimethylformamide acetals and Bredereck’s reagent (tert-butoxy-bis(dimethylamino) methane) are versatile C1 building blocks due to their ability to undergo condensation reactions with CH-acidic methyl and methylene moieties. Subsequent modulation of the resulting condensation products enables the preparation of open-chain products like aldehydes, ketones, enones, enol ethers, methyl groups, and, most important in alkaloid total synthesis, the annulation of heterocyclic rings like pyridines, pyridine-N-oxides, bromopyridines, aminopyridines, aminopyrimidines, pyrroles and chromenones. In certain cases, these reagents can act as alkylating agents. The applications of these building blocks in natural products total synthesis are reviewed here.

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