scholarly journals The Calyciphylline B-type Alkaloids: Total Syntheses of (–)-Daphlongamine H and (–)-Isodaphlongamine H

2019 ◽  
Author(s):  
Cedric Hugelshofer ◽  
Vignesh Palani ◽  
Richmond Sarpong
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Mannich Reaction ◽  
Biosynthetic Pathway ◽  
Total Syntheses ◽  
Diastereoselective Hydrogenation ◽  
Tricyclic Core ◽  
Synthetic Studies

The first total synthesis of the complex hexacylic Daphniphyllum alkaloid (–)-daphlongamine H in enantioenriched form has been accomplished. Key to the success of the strategy are a complexity-building Mannich reaction, efficient cyclizations, and a highly diastereoselective hydrogenation to assemble multigram quantities of the tricyclic core bearing four contiguous stereocenters. Following construction of the hydro-indene substructure by means of a Pauson–Khand reaction, endgame redox manipulations delivered the natural product. Importantly, the synthetic studies have also given access to (–)-isodaphlongamine H and led to a revision of the reported structure of deoxyisocalyciphylline B, which resulted in the proposal of a modified biosynthetic pathway to the calyciphylline B-type alkaloids.

scholarly journals The Calyciphylline B-type Alkaloids: Total Syntheses of (–)-Daphlongamine H and (–)-Isodaphlongamine H

2019 ◽  
Author(s):  
Cedric Hugelshofer ◽  
Vignesh Palani ◽  
Richmond Sarpong
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Mannich Reaction ◽  
Biosynthetic Pathway ◽  
Total Syntheses ◽  
Diastereoselective Hydrogenation ◽  
Tricyclic Core ◽  
Synthetic Studies

The first total synthesis of the complex hexacylic Daphniphyllum alkaloid (–)-daphlongamine H in enantioenriched form has been accomplished. Key to the success of the strategy are a complexity-building Mannich reaction, efficient cyclizations, and a highly diastereoselective hydrogenation to assemble multigram quantities of the tricyclic core bearing four contiguous stereocenters. Following construction of the hydro-indene substructure by means of a Pauson–Khand reaction, endgame redox manipulations delivered the natural product. Importantly, the synthetic studies have also given access to (–)-isodaphlongamine H and led to a revision of the reported structure of deoxyisocalyciphylline B, which resulted in the proposal of a modified biosynthetic pathway to the calyciphylline B-type alkaloids.

Isolation, Synthesis, and Biological Activity of Quindoline, a Valuable­ Indoloquinoline Natural Product and Useful Key Intermediate­

Synthesis ◽  
2018 ◽  
Vol 50 (07) ◽  
pp. 1417-1429 ◽  
Author(s):  
Teodoro Kaufman ◽  
María Méndez ◽  
Andrea Bracca
Keyword(s):  
Biological Activity ◽  
Total Synthesis ◽  
Natural Product ◽  
Natural Source ◽  
Total Syntheses ◽  
Naturally Occurring ◽  
The World ◽  
Biological Tests ◽  
Synthetic Studies

Quindoline is one of the simplest naturally occurring monomeric indoloquinoline alkaloids. Chemists exhibited interest in this compound before it was isolated from a natural source. The different approaches toward the total synthesis of the natural product and its performance in various biological tests are discussed. Aspects related to the isolation of quindoline from different ethnomedicinally relevant plants around the world are also reviewed.1 Introduction2 Isolation and Biogenetic Considerations3 Total Syntheses of Quindoline3.1 Early Synthetic Studies3.2 Syntheses from Benzenoids3.3 Syntheses from Indoles3.4 Syntheses from Quinolines4 Biological Activity Studies5 Conclusions

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.

scholarly journals Evolution of Pauson-Khand Reaction: Strategic Applications in Total Syntheses of Architecturally Complex Natural Products (2016–2020)

Catalysts ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1199
Author(s):  
Sijia Chen ◽  
Chongguo Jiang ◽  
Nan Zheng ◽  
Zhen Yang ◽  
Lili Shi
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Natural Product ◽  
Organic Synthesis ◽  
Total Syntheses

Metal-mediated cyclizations are important transformations in a natural product total synthesis. The Pauson-Khand reaction, particularly powerful for establishing cyclopentenone-containing structures, is distinguished as one of the most attractive annulation processes routinely employed in synthesis campaigns. This review covers Co, Rh, and Pd catalyzed Pauson-Khand reaction and summarizes its strategic applications in total syntheses of structurally complex natural products in the last five years. Additionally, the hetero-Pauson-Khand reaction in the synthesis of heterocycles will also be discussed. Focusing on the panorama of organic synthesis, this review highlights the strategically developed Pauson-Khand reaction in fulfilling total synthetic tasks and its synthetic attractiveness is aimed to be illustrated.

scholarly journals Recent Chemical Methodology Advances in the Total Synthesis of Meroterpenoids

2021 ◽  
Vol 68 (2) ◽  
pp. 247-267
Author(s):  
Jan Petrovčič ◽  
Chad Nicholas Ungarean ◽  
David Sarlah
Keyword(s):  
Organic Chemistry ◽  
Natural Products ◽  
Total Synthesis ◽  
Feature Article ◽  
Total Syntheses ◽  
Synthetic Organic Chemistry ◽  
Synthetic Studies

Heterogeneity of meroterpenoids arising from their dual biosynthetic origins is constantly provoking synthetic chemists to utilize their ingenuity and revise their retrosynthetic logic. By studying recent publications on meroterpenoid synthesis,tremendous advances in the field of synthetic organic chemistry can be witnessed. This feature article covers some of the most intriguing total syntheses and synthetic studies towards the meroterpenoid class of natural products from the last five years.

Synthesis of the fatty acid of pramanicin

1997 ◽  
Vol 75 (6) ◽  
pp. 884-889 ◽  
Author(s):  
Christopher Cow ◽  
David Valentini ◽  
Paul Harrison
Keyword(s):  
Natural Products ◽  
Fatty Acid ◽  
Total Synthesis ◽  
Natural Product ◽  
Biosynthetic Pathway ◽  
Decanoic Acid ◽  
Enoic Acid ◽  
Reaction Sequence ◽  
Racemic Form ◽  
Biomimetic Approach

The natural product tetradec-2-enoic acid-4,5-epoxide (2), which is also a component of the antibiotic pramanicin (1), was prepared in racemic form by a glycoluril-template directed approach. Two sequential additions of acetate units to decanoic acid are effected by intramolecular condensations on the template, mimicking the proposed biosynthetic pathway to 1. Cleavage of the grown trans,trans-tetradeca-2,4-dienoyl chain from the template and epoxidation yields 2. The reaction sequence illustrates the applicability of this biomimetic approach to total synthesis of natural products. Keywords: pramanicin, biomimetic, glycoluril, template.

Total synthesis of cytotoxic marine macrolides: Callipeltoside A, aurisides A and B, and dolastatin 19

2008 ◽  
Vol 80 (8) ◽  
pp. 1773-1782 ◽  
Author(s):  
Ian Paterson ◽  
Alison D. Findlay
Keyword(s):  
Total Synthesis ◽  
Conformational Analysis ◽  
Marine Origin ◽  
Total Syntheses ◽  
Stereochemical Assignment ◽  
Callipeltoside A ◽  
Marine Macrolides ◽  
Synthetic Studies

Synthetic studies pertaining to a novel class of structurally related glycosidic 14-membered macrolides of marine origin are reported. The evolution of a versatile aldol-based strategy that culminated in the total syntheses of callipeltoside A and aurisides A and B is detailed. Using a combination of biogenetic considerations and conformational analysis, a revised stereochemical assignment for the related polyketide dolastatin 19 was proposed and validated by total synthesis.

scholarly journals On the Structure of (R)-2-Methylheptyl Isonicotinate: Evidence for the Structural Solution from Total Synthesis

2018 ◽  
Vol 13 (3) ◽  
pp. 1934578X1801300
Author(s):  
Mangala Gowri Ponnapalli ◽  
Narayana Rao Gundoju ◽  
Harikiran Theerthala ◽  
Ramesh Bokam ◽  
Nageswara Rao Yalavarthi
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Molecular Identification ◽  
Total Syntheses ◽  
Ethylhexyl Phthalate ◽  
Microbial Agent ◽  
Structural Solution

The controversial molecular identification of ( R)-2-methylheptyl isonicotinate (1) has been settled. Despite its significance as a potent anti-microbial agent against several clinically relevant pathogens, the structure of natural product is uncertain so far due to controversial reports. Its structure has been resolved as bis (2-ethylhexyl) phthalate (2) by total syntheses of chain isomers. In addition, we have also revised bis (2-methylheptyl) phthalate (3) as (2) in some reports.

scholarly journals A Concise Total Synthesis of the Fungal Isoquinoline Alkaloid TMC-120B

Molecules ◽  
2022 ◽  
Vol 27 (2) ◽  
pp. 521
Author(s):  
Ahmad K. Haidar ◽  
Niels D. Kjeldsen ◽  
Nikolaj S. Troelsen ◽  
Viola Previtali ◽  
Kasper P. Lundquist ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Isoquinoline Alkaloid ◽  
Total Syntheses ◽  
Antiepileptic Activity ◽  
Short Synthesis

Recent reports of antiepileptic activity of the fungal alkaloid TMC-120B have renewed the interest in this natural product. Previous total syntheses of TMC-120B comprise many steps and have low overall yields (11–17 steps, 1.5–2.9% yield). Thus, to access this compound more efficiently, we herein present a concise and significantly improved total synthesis of the natural product. Our short synthesis relies on two key cyclization steps to assemble the central scaffold: isoquinoline formation via an ethynyl-imino cyclization and an intramolecular Friedel-Crafts reaction to form the furanone.

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