An Expeditious Route for the Total Synthesis of Pondaplin Isolated from Annona glabra

A novel cyclic prenylated phenylpropanoid, pondaplin 1, was first synthesized in 26% overall yields through an expeditious route (7 steps) that employed highly regio- and stereoselective phenyltellurenylation to arylacetylene and palladium (II) chloride-catalyzed carbonylation of hydroxy styryl phenyl telluride as key steps.

The First Total Synthesis of Five Elegan Type Natural Products

The first total synthesis of five linear diterpenes: eleganolone (1), eleganolone acetate (2), elegandiol (3), eleganonal (4) and epoxyeleganolone (5), was achieved from (E,E)-farnesol (6) via 4 to 6 steps. The key step was the alkylation reaction of silyl cyanide with allylic iodide.

Efficient and collective total synthesis of natural products via radical cascade reactions

Subject Code:B02With the support of the National Natural Science Foundation of China,the research team led by Prof.Qin Yong(秦勇)at Sichuan University accomplished a collective synthesis of 33 monoterpenoid indole alkaloids that belong to four families,by developing new photoredox-initiated radical cascade reactions.

Progress on the total synthesis of natural products in China:From 2006 to 2010

This paper summarizes the progress on the total syntheses riod from 2006 to 2010. The overview focuses on the first of natural products accomplished in rnainland China during the petotal synthesis of natural products of contemporary interest includ- ing alkaloids, cyclopeptides and cyclic depsipeptides, macrolides, terpenoids and steroids, saponins and glycosides. The development of novel synthetic strategies and methodologies, and application of new selective synthetic methods in the total syntheses of natural products are included as well.

Asymmetric construction of all-carbon quaternary stereocenters in the total synthesis of natural products

Structure units containing all-carbon quaternary stereogenic center are found in many bioactive natural products. However, enantioselective construction of this type of structure units has been a formidable challenge for synthetic community due to the steric hindrance enforced by all-carbon quatemary stereocenters. In this review, we present the achievements made by Chinese scientists in the area of asymmetric synthesis of all-carbon quaternary stereocenters in natural products during the past two years.

Enantioselective Total Synthesis of(+)-Propolisbenzofuran B

Comprehensive Summary The first catalytic asymmetric total synthesis of(+)-propolisbenzofuran B,enabled by a highly enantioselective rhodium-catalyzed hydrogenation of a tetrasubstituted olefin,was described.Other noteworthy aspects include the construction of the central hydrodibenzo[b,d]furan core through a sequence of Zn(II)-mediated regioselective benzofuran formation and Dieckmann condensation,as well as C-H oxidations,involving a visible light-induced Fe(III)-catalyzed benzylic C(sp3)-H oxidation.Additionally,the absolute configuration was confirmed by X-ray analysis of a carbonate intermediate.

Divergent total synthesis of marine meroterpenoids(+)-dysidavarones A–C

Here,we report a concise and divergent enantioselective total synthesis of marine sesquiterpene quinone meroterpenoids(+)-dysidavarones A–C(1–3)using predysidavarone 6 as a key common intermediate.The highly strained and bridged eight-membered carbocycle of predysidavarone 6 was constructed by a one-pot intermolecular alkylation and intramolecular arylation of Wieland–Miescher ketone derivative 11 and benzyl bromide 12.The total synthesis of(+)-dysidavarones A–C(1–3)was achieved from predysidavarone 6 in a divergent manner by a late-stage introduction of the ethoxy group,which reveals the possible source of the ethoxy group within(+)-dysidavarones A–C(1–3)and provides a late-stage modifiable route for the synthesis of dysidavarone analogs for further anti-cancer activity evaluation.

First Total Synthesis of （±）-Puyanin and （±）-4＇-O-Methylbonannione

A facile approach for the first total synthesis of two naturally occurring geranylated flavonoids, （±）-puyanin （1） and （±）-4＇-O-methylbonannione （2） has been obtained with total yields of 27% and 17.8%, respectively. The key steps were regioselective cyclization of geranylated trihydroxychalcone and regioselective geranylation of 2,4,6-trihydroxyacetophenone.

Protecting-Group-Free Total Synthesis of(-)-Pallambins A-D

Main observation and conclusion A full account of the total synthesis of(-)-pallambins A-D(1-6)is described.The strategy was devised by simulating their biosynthetic pathway.The left-part bicyclo[3.2.1]octane system of pallambins C and D was efficiently constructed via a palladium-catalyzed oxidative cyclization.

Seven-step total synthesis of α-cyclopiazonic acid

A seven-step total synthesis of α-cyclopiazonic acid is reported from a commercially available 4-bromoindole.Salient feature of the work is the rapid formation of tetracyclic skeleton via a bioinspired [3+2] annulation to form the C/D rings.

Enantioselective total synthesis of (+)-vincamine

A catalytic asymmetric total synthesis of(+)-vincamine is presented. Key features of the synthesis include a Pd-catalyzed enantioselective decarboxylative allylation to form the C20 quaternary stereogenic center and a stereoselective iminium reduction to install the critical cis-C20/C21 relative stereochemisty.

Bioinspired Scalable Total Synthesis of Opioids

As one of the largest and most representative families of natural medicines harvested from plants,the mass production of opioids legitimately occupies large,worldwide farmland cultivation of opium poppies,causing severe regulation limitations and supply uncertainty.Due to their complex structures,the chemical synthesis of opioids has been criticized as infeasible for large-scale production in view of lengthy synthetic steps and overall low efficiency.

Recent advances in the total synthesis of monoterpenoid indole alkaloids enabled by asymmetric catalysis

Asymmetric catalysis has continued to enable the preparation of optically active natural products over the past decade.This minireview summarizes progress in the catalytic enantioselective total synthesis of complex monoterpenoid indole alkaloids covering the reports from 2019 to June 2021.In particular,the generation of the key chiral stereogenic centers with metal catalysts and organocatalysts has been highlighted,showcasing the power of asymmetric catalysis protocols in accessing complex molecular architectures.

Strategies for constructing seven-membered rings:Applications in natural product synthesis

The seven-membered ring motifs are found in bioactive pharmaceuticals and a wide range of natural products,including alkaloids and terpenoids,which hold significant importance in synthetic chemistry and has garnered considerable attention from both academia and industry.Despite the challenges faced in the past decade,the total synthesis of natural products incorporating the non-aromatic cycloheptane skeletons remains a compelling pursuit.Recently,numerous elegant strategies for constructing the sevenmembered ring system have been successfully developed.This review focuses on the recent advancements in this field from 2017 to April 2023,highlighting key transformations utilized to construct the non-aromatic cycloheptane core structures and serves as a valuable guide for synthetic chemists engaged in the total synthesis of natural products containing seven-membered ring motifs.

Synthesis of Cytotoxic Sinapyl Alcohol Derivatives fromLigularia nelumbifolia

Total synthesis of two cytotoxic natural products, nelumol A (1) and nelumal A (2), were carried out by two different paths. 4-O-Benzyl substitute analogues 26 and 27, as well as the 4-O-(2-methyl-butenyl) derivatives 29 and 30 were also synthesized for a SAR investigation. 1 and 2 were also measured on different tumor cell line.

海洋生物碱Aaptamine的全合成

目的设计了一条高效的海洋生物碱Aaptamine的合成路线。方法该合成路线使用廉价易得的6,7-二甲氧基四氢异喹啉为原料,经过六步反应成功合成目标天然产物,总产率约为21%。全合成中的关键步骤包括甲基化反应和在布朗斯特酸的作用下,Vilsmeier试剂促进关环生成苯并[de][1,6]萘啶骨架结构。结论关键中间体和产物结构经~1H-NMR、~(13)C-NMR和HR-MS(ESI)进行了确证。本文所提供的合成路线简单易行、合成步骤相对较短,为Aaptamine类生物碱的开发应用奠定了基础。

Total Synthesis and Stereochemical Assignment of Talaroconvolutin A and Talarofuranone: Gram-scale Synthesis of Ferroptosis Inducer Talaroconvolutin A

The first total synthesis of talaroconvolutin A(1.1 g obtained)and talarofuranone has been achieved using accessible materials(12 steps,7.5%and 8.2%yields,respectively).Convergent routes involved intramolecular Diels-Alder reactions in two approaches for creating the decalin moiety.Additionally,an unprecedented DMP-mediated domino reaction resulted in the deoxy-tetramic acid system.These syntheses not only establish the absolute configuration of talaroconvolutin A but also enable further collaborative studies of this typeofferroptosisinducers.

Advances of radical and photo reactions in natural products synthesis

This review will focus on the recent advances of radical and photo reactions and their applications in the natural products total synthesis. A brief introduction to the development and mechanism of the newly developed radical and photo reactions will be presented. The organization of the each section is based on the type of reactions used. Examples of synthetic applications are discussed to demonstrate the potential of related methodologies and inspire future explorations.

C–H bond activation in the total syntheses of natural products

The transition metal-mediated C–H bond activation has emerged as a powerful and ideal method for the total syntheses of natural products and pharmaceuticals, and has had a significant impact on synthetic planning and strategy in complex natural products.In this review, we describe selected recent examples of the transition metal-mediated C–H bond activation strategies for the rapid syntheses of natural products.