scholarly journals Total Synthesis and Late‐Stage C–H Oxidations of ent‐Trachylobane Natural Products

2021 ◽  
Author(s):  
Lukas Anton Wein ◽  
Klaus Wurst ◽  
Thomas Magauer
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Late Stage

Synthetic approaches to [5,6]-benzannulated spiroketal natural products

2011 ◽  
Vol 84 (6) ◽  
pp. 1379-1390 ◽  
Author(s):  
Michael C. McLeod ◽  
Margaret A. Brimble ◽  
Dominea C. K. Rathwell ◽  
Zoe E. Wilson ◽  
Tsz-Ying Yuen
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Electronic Properties ◽  
Late Stage ◽  
Biologically Active ◽  
Formal Synthesis ◽  
Berkelic Acid ◽  
Synthetic Approaches

Studies toward the synthesis of three biologically active [5,6]-benzannulated spiroketal natural products are described. The first total synthesis of paecilospirone is reported, employing a late-stage, pH-neutral spiroketalization. A formal synthesis of γ-rubromycin is described, where the spiroketal moiety is formed by delicate manipulation of the electronic properties of the spirocyclization precursor. Finally, model work toward the total synthesis of berkelic acid is summarized, introducing a novel Horner–Wadsworth–Emmons/oxa-Michael (HWE/oxa-M) cascade to access the spiroketal precursor.

scholarly journals Total Synthesis of Phorbazole B

Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4848
Author(s):  
Yngve Guttormsen ◽  
Magnus E. Fairhurst ◽  
Sunil K. Pandey ◽  
Johan Isaksson ◽  
Bengt Erik Haug ◽  
...  
Keyword(s):  
Natural Products ◽  
High Resolution ◽  
Secondary Metabolites ◽  
Total Synthesis ◽  
Cancer Cells ◽  
Marine Sponge ◽  
Inhibitory Activity ◽  
Late Stage ◽  
Nmr Techniques

Phorbazoles are polychlorinated heterocyclic secondary metabolites isolated from a marine sponge and several of these natural products have shown inhibitory activity against cancer cells. In this work, a synthesis of the trichlorinated phorbazole B using late stage electrophilic chlorination was developed. The synthesis relied on the use of an oxazole precursor, which was protected with an iodine in the reactive 4-position, followed by complete chlorination of all pyrrole positions. Attempts to prepare phorbazole A and C, which contain a 3,4-dichlorinated pyrrole, were unsuccessful as the desired chlorination pattern on the pyrrole could not be obtained. The identities of the dichlorinated intermediates and products were determined using NMR techniques including NOESY/ROESY, 1,1-ADEQUATE and high-resolution CLIP-HSQMBC.

scholarly journals Total synthesis of the actinoallolides and a designed photoaffinity probe for target identification

2020 ◽  
Vol 18 (40) ◽  
pp. 8109-8118
Author(s):  
Matthew J. Anketell ◽  
Theodore M. Sharrock ◽  
Ian Paterson
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Late Stage ◽  
Target Identification ◽  
Convergent Synthesis

A convergent synthesis of the actinoallolides with late-stage diversification provides access to a photoaffinity probe to identify the target of these potent anti-trypanosomal natural products.

Tungsten-Promoted Hetero-Pauson–Khand Cycloaddition: Application to the Total Synthesis of (–)-Allosecurinine

Synthesis ◽  
2019 ◽  
Vol 51 (09) ◽  
pp. 2001-2006 ◽  
Author(s):  
Egor Chirkin ◽  
Chouaha Bouzidi ◽  
François-Hugues Porée
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Intramolecular Cyclization ◽  
Late Stage ◽  
Ring System ◽  
Enantioselective Synthesis

Herein, we report a concise enantioselective synthesis of (–)-allosecurinine, a tetracyclic Securinega alkaloid featuring an α,β-unsaturated γ-lactone moiety. Starting from inexpensive and readily available trans-l-hydroxyproline, our strategy entails a rare late-stage [2+2+1]-hetero-Pauson–Khand cycloaddition between a ketone and an alkyne as the key complexity-generating step to rapidly install the CD-ring system. The reported W(CO)6-promoted intramolecular cyclization provides the first example of a tungsten-mediated hetero-Pauson–Khand reaction. This approach to the strained bicyclic CD motif present in ­allosecurinine provides some insights into the boundaries of this potentially powerful methodology that might be further extended to other butenolide-containing natural products.

scholarly journals Total synthesis of biseokeaniamides A–C and late-stage electrochemically-enabled peptide analogue synthesis

2020 ◽  
Vol 11 (39) ◽  
pp. 10752-10758 ◽  
Author(s):  
Yutong Lin ◽  
Lara R. Malins
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Late Stage ◽  
Peptide Analogue ◽  
Rapid Access ◽  
Structural Analogues

A late-stage electrochemical decarboxylation enables rapid access to structural analogues of biseokeaniamides A–C, cytotoxic lipopeptide natural products.

scholarly journals Divergent Strategy in Marine Tetracyclic Meroterpenoids Synthesis

Marine Drugs ◽  
2021 ◽  
Vol 19 (5) ◽  
pp. 273
Author(s):  
Antonio Rosales Martínez ◽  
Ignacio Rodríguez-García ◽  
Josefa L. López-Martínez
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Natural Product ◽  
Organic Synthesis ◽  
Late Stage ◽  
Marine Natural Product ◽  
Synthesis Strategy ◽  
Related Compounds

The divergent total synthesis strategy can be successfully applied to the preparation of families of natural products using a common late-stage pluripotent intermediate. This approach is a powerful tool in organic synthesis as it offers opportunities for the efficient preparation of structurally related compounds. This article reviews the synthesis of the marine natural product aureol, as well as its use as a common intermediate in the divergent synthesis of other marine natural and non-natural tetracyclic meroterpenoids.

Synthesis of Spongidine A, D and Petrosaspongiolide L Methyl Ester Using Pyridine C-H Functionalization

2019 ◽  
Author(s):  
Florian Bartels ◽  
Manuela Weber ◽  
Mathias Christmann
Keyword(s):  
Natural Products ◽  
Methyl Ester ◽  
Hydrogen Atom ◽  
Phospholipase A2 ◽  
Late Stage ◽  
Hydrogen Atom Transfer ◽  
Ring System ◽  
Tetracyclic Core ◽  
Intramolecular Hydrogen ◽  
Phospholipase A2 Inhibitors

<div>An efficient strategy for the synthesis of the potent phospholipase A2 inhibitors spongidine A and D is presented. The tetracyclic core of the natural products was assembled via an intramolecular hydrogen atom transfer‐initiated Minisci reaction. A divergent late‐stage functionalization of the tetracyclic ring system was also used to achieve a concise synthesis of petrosaspongiolide L methyl ester.</div>

Convergent Total Synthesis of Principinol D, a Rearranged Kaurane Diterpenoid

2019 ◽  
Author(s):  
Timothy Newhouse ◽  
Aneta Turlik ◽  
Yifeng Chen ◽  
Anthony Scruse
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Late Stage ◽  
Membered Ring ◽  
Entry Point ◽  
Ketone Reduction ◽  
Coupling Approach

<div> <p>The total synthesis of principinol D, a rearranged kaurane diterpenoid, is reported. This grayanane natural product is constructed via a convergent fragment coupling approach, wherein the central 7-membered ring is synthesized at a late stage. The bicyclo[3.2.1]octane fragment is accessed by a Ni-catalyzed α-vinylation reaction. Strategic reductions include a diastereoselective SmI<sub>2</sub>-mediated ketone reduction with PhSH and a new protocol for selective ester reduction in the presence of ketones. The convergent strategy reported herein may be an entry point to the larger class of kaurane diterpenoids.</p> </div>

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>

Sign in / Sign up

Export Citation Format

Share Document