ChemInform Abstract: Total Synthesis of ent-(-)-Azonazine Using a Biomimetic Direct Oxidative Cyclization and Structural Reassignment of Natural Product.

(+)-Bovidic acid is an 18-carbon hydroxyfuranoid acid isolated from the pelage of the gaur (Bos frontalis) and displays potential as an insect repellant. Both a formal and total synthesis of (+)-bovidic acid was carried out with the core of the natural product being synthesized through Mukaiyama aerobic oxidative cyclization employing the second-generation Co(nmp)2 catalyst.

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Synthesis of highly substituted fluorenones via metal-free TBHP-promoted oxidative cyclization of 2-(aminomethyl)biphenyls. Application to the total synthesis of nobilone

Beilstein Journal of Organic Chemistry ◽

10.3762/bjoc.17.181 ◽

2021 ◽

Vol 17 ◽

pp. 2668-2679

Author(s):

Ilya A P Jourjine ◽

Lukas Zeisel ◽

Jürgen Krauß ◽

Franz Bracher

Keyword(s):

Total Synthesis ◽

Natural Product ◽

Functional Groups ◽

Oxidative Cyclization ◽

Metal Free ◽

Dehydrogenative Coupling ◽

Protective Groups

Highly substituted fluorenones are readily prepared in mostly fair to good yields via metal- and additive-free TBHP-promoted cross-dehydrogenative coupling (CDC) of readily accessible N-methyl-2-(aminomethyl)biphenyls and 2-(aminomethyl)biphenyls. This methodology is compatible with numerous functional groups (methoxy, cyano, nitro, chloro, and SEM and TBS-protective groups for phenols) and was further utilized in the first total synthesis of the natural product nobilone.

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Total synthesis of ent-(−)-azonazine using a biomimetic direct oxidative cyclization and structural reassignment of natural product

Tetrahedron ◽

10.1016/j.tet.2014.03.061 ◽

2014 ◽

Vol 70 (19) ◽

pp. 3197-3210 ◽

Cited By ~ 18

Author(s):

Ji-Chen Zhao ◽

Shun-Ming Yu ◽

Hai-Bo Qiu ◽

Zhu-Jun Yao

Keyword(s):

Total Synthesis ◽

Natural Product ◽

Oxidative Cyclization

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Progress Toward The Total Synthesis Of The Marine Natural Product Karlotoxin 5

Planta Medica ◽

10.1055/s-0033-1348824 ◽

2013 ◽

Vol 79 (10) ◽

Author(s):

M Albadry ◽

Y Zou ◽

Y Takahashi ◽

A Waters ◽

M Hossein ◽

...

Keyword(s):

Total Synthesis ◽

Natural Product ◽

Marine Natural Product

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Bioactivity-guided retrosynthesis: “Upping the ante” for natural product total synthesis

Planta Medica ◽

10.1055/s-0035-1556096 ◽

2015 ◽

Vol 81 (11) ◽

Author(s):

D Romo

Keyword(s):

Total Synthesis ◽

Natural Product

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Total Synthesis of the Antitumor Depsipeptide FE399 and its S-Benzyl Derivative: A Macrolactamization Approach

10.26434/chemrxiv.12017796.v1 ◽

2020 ◽

Author(s):

Takayuki Tonoi ◽

Miyuki Ikeda ◽

Teruyuki Sato ◽

Ryo Kawahara ◽

Takatsugu Murata ◽

...

Keyword(s):

Molecular Structure ◽

Total Synthesis ◽

Natural Product ◽

Condensation Reaction ◽

Practical Method ◽

Equilibrium Mixture ◽

Conformational Isomers ◽

Single Isomer

<div>An efficient and practical method for the synthesis of (9R,14R,17R)-FE399, a novel antitumor bicyclic depsipeptide, was developed. A 2-methyl-6-nitrobenzoic anhydride (MNBA)-mediated dehydration condensation reaction was effectively employed for the formation of the 16-membered macrocyclic depsipeptide moiety of FE399. FE399 was found to exist as an inseparable equilibrium mixture of conformational isomers; the mixture was quantitatively transformed into the corresponding S-benzyl product and isolated as a single isomer. Thus, we could confirm that the molecular structure of FE399 obtained by this method is identical to that of the natural product.</div>

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

10.26434/chemrxiv.6405761.v1 ◽

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.

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Convergent Total Synthesis of Principinol D, a Rearranged Kaurane Diterpenoid

10.26434/chemrxiv.7865168.v4 ◽

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>

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A Short Synthesis of (+)-Brefeldin C via Enantioselective Radical Hydroalkynylation

10.26434/chemrxiv.8397731.v1 ◽

2019 ◽

Author(s):

Lars Gnägi ◽

Severin Vital Martz ◽

Daniel Meyer ◽

Robin Marc Schärer ◽

Philippe Renaud

Keyword(s):

Total Synthesis ◽

Natural Product ◽

Oxidation State ◽

Single Step ◽

Radical Process ◽

Target Molecule ◽

Short Synthesis ◽

The One

<div><div><div><div><p>A very concise total synthesis of (+)-brefeldin C starting from 2-furanylcyclopentene is described. This approach is based on an unprecedented enantioselective radical hydroalkynylation process to introduce the two cyclopentane stereocenters in a single step. The use of a furan substituent allows to achieve a high trans diastereoselectivity during the radical process and it contains the four carbon atoms C1–C4 of the natural product in an oxidation state closely related to the one of the target molecule. The eight-step synthesis require six product purifications and it provides (+)-brefeldin C in 18% overall yield.</p></div></div></div></div>

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