Synthesis, α-mannosidase inhibition studies and molecular modeling of 1,4-imino-ᴅ-lyxitols and their C-5-altered N-arylalkyl derivatives

• Martin Kalník,
• Sergej Šesták,
• Juraj Kóňa,
• Maroš Bella and
• Monika Poláková

Beilstein J. Org. Chem. 2023, 19, 282–293, doi:10.3762/bjoc.19.24

• .19.24 Abstract A synthesis of 1,4-imino-ᴅ-lyxitols and their N-arylalkyl derivatives altered at C-5 is reported. Their inhibitory activity and selectivity toward four GH38 α-mannosidases (two Golgi types: GMIIb from Drosophila melanogaster and AMAN-2 from Caenorhabditis elegans, and two lysosomal types

• successful [25][26][27]. The only exception is the latest study by Cheng et al. who reported breakthrough findings in the development of highly potent and selective human GMII inhibitors. A combination of natural product-inspired combinatorial chemistry and computation-guided synthesis provided a nanomolar

• ], indicating that they are more suitable candidates for the next-generation design of potent and selective GMII inhibitors. Therefore, the current study is dedicated to designing further modifications of these analogs. This contribution deals with the synthesis of 1,4-imino-ᴅ-lyxitols altered at C-5 and

Strategies to access the [5-8] bicyclic core encountered in the sesquiterpene, diterpene and sesterterpene series

• Cécile Alleman,
• Charlène Gadais,
• Laurent Legentil and
• François-Hugues Porée

Beilstein J. Org. Chem. 2023, 19, 245–281, doi:10.3762/bjoc.19.23

• cyclooctane ring fused to a cyclopentane ring, i.e., a [5-8] bicyclic ring system. This review focuses on the different strategies elaborated to construct this [5-8] bicyclic ring system and their application in the total synthesis of terpenes over the last two decades. The overall approaches involve the

• bicyclic system. This review focuses on the different strategies elaborated to build this [5-8] bicyclic ring system and their applications in the total synthesis of terpenes over the last two decades [3]. We are not providing here a comprehensive collection of the literature. When appropriate, the reader

• following criteria: position/stage of the key cyclooctane ring formation in the synthesis plan, the selectivity, and the opportunity for late-stage functionalization. Review 1 Metathesis: ring-closing metathesis and related methods The metathesis reaction, first discovered by serendipity in the 1950s, has

An efficient metal-free and catalyst-free C–S/C–O bond-formation strategy: synthesis of pyrazole-conjugated thioamides and amides

• Shubham Sharma,
• Dharmender Singh,
• Sunit Kumar,
• Vaishali,
• Rahul Jamra,
• Naveen Banyal,
• Deepika,
• Chandi C. Malakar and
• Virender Singh

Beilstein J. Org. Chem. 2023, 19, 231–244, doi:10.3762/bjoc.19.22

• Department of Chemistry, Central University of Punjab, Bathinda, 151401, Punjab, India, Department of Chemistry, National Institute of Technology (NIT) Manipur, Imphal, 795004, India 10.3762/bjoc.19.22 Abstract An operationally simple and metal-free approach is described for the synthesis of pyrazole

• rearrangement [57]. Although, these protocols are useful and have exhibited wide applications in organic synthesis (Figure 2), the scope of these reported methods may suffer from drawbacks such as harsh reaction conditions, use of expensive reagents, prolonged reaction times, low product yields, and cumbersome

• of base/catalyst and limitation of starting reagents [63][64]. Our current work was completed with the exploration of the position of the pyrazole ring like C-3, C-4 and C-5 and we also employed the pyrazole-based AXB3s (4-iodo-C-3 and 4-iodo-C-5). Moreover, we also disclosed the synthesis of

Investigation of cationic ring-opening polymerization of 2-oxazolines in the “green” solvent dihydrolevoglucosenone

• Solomiia Borova and
• Robert Luxenhofer

Beilstein J. Org. Chem. 2023, 19, 217–230, doi:10.3762/bjoc.19.21

• Solomiia Borova Robert Luxenhofer Functional Polymer Materials, Chair for Advanced Materials Synthesis, Institute for Functional Materials and Biofabrication, Department of Chemistry and Pharmacy, Julius-Maximilans-University of Würzburg, Röntgenring 11, 97070 Würzburg, Germany Soft Matter

• biomedical applications in, e.g., drug delivery systems, tissue engineering and more. Commonly, the synthesis of poly(2-oxazoline)s involves problematic organic solvents that are not ideal from a safety and sustainability point of view. In this study, we investigated the cationic ring-opening polymerization

• Hydrophilic synthetic polymers are interesting for a wide range of applications, including in the biomedical field. The synthesis of these polymers often requires the use of various organic solvents. However, most of the used solvents are undesirable on a large scale for health, safety, and environmental

Friedel–Crafts acylation of benzene derivatives in tunable aryl alkyl ionic liquids (TAAILs)

• Swantje Lerch,
• Stefan Fritsch and
• Thomas Strassner

Beilstein J. Org. Chem. 2023, 19, 212–216, doi:10.3762/bjoc.19.20

• acylation; homogeneous catalysis; ionic liquids; iron catalysis; TAAILs; Introduction The Friedel–Crafts acylation is one of the oldest metal-catalyzed reactions in organic chemistry [1] and allows for the synthesis of a broad range of diverse compounds [2][3][4][5]. Starting from electron-rich aromatic

• proved to be a potent reaction medium in catalytic hydrosilylation [53], hydroamination and hydroarylation [54], as well as for the synthesis of nanoparticles [55][56]. Results and Discussion Ionic liquids 1–6 were synthesized via a three-step procedure starting from commercially available aniline

• liquid and the TAAILs outperform commercially available ILs in our model reaction. Time-dependent analysis of the reaction using varying amounts of anhydride. Reaction conditions: 1 mmol anisole, 1.3–3.0 equiv Ac2O, 10 mol % FeCl3·6H2O, T = 60 °C, 0.5 g TAAIL 6. Synthesis of TAAILs. i) 1 equiv glyoxal

An accelerated Rauhut–Currier dimerization enabled the synthesis of (±)-incarvilleatone and anticancer studies

• Tharun K. Kotammagari,
• Sweta Misra,
• Sayantan Paul,
• Sunita Kunte,
• Rajesh G. Gonnade,
• Manas K. Santra and
• Asish K. Bhattacharya

Beilstein J. Org. Chem. 2023, 19, 204–211, doi:10.3762/bjoc.19.19

• The total synthesis of racemic incarvilleatone has been achieved by utilizing unexplored accelerated Rauhut–Currier (RC) dimerization. The other key steps of the synthesis are oxa-Michael and aldol reactions in a tandem sequence. Racemic incarvilleatone was separated by chiral HPLC and the

• configuration of each enantiomer was determined by single-crystal X-ray analysis. In addition, a one-pot synthesis of (±)-incarviditone has been achieved from rac-rengyolone by using KHMDS as a base. We have also assessed the anticancer activity of all the synthesized compounds in breast cancer cells

• displayed cytotoxicity against the HL-60 cell line with an IC50 value of 14.8 mg/mL and against the 6T-CEM cell line with an IC50 value of 22.2 mg/mL. Lawrence et al. [3] and Tang et al. [4] have reported the synthesis of (±)-incarvilleatone (1) and (±)-incarviditone (2) via biomimetic dimerization of

Germacrene B – a central intermediate in sesquiterpene biosynthesis

• Houchao Xu and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2023, 19, 186–203, doi:10.3762/bjoc.19.18

• synthesis from β-eudesmol (30) through epoxidation to 31, dehydration to 32 and epoxide opening with LiAlH4 yielded (−)-11 (Scheme 9C) [77], contradicting this assignment. Notably, Šorm and co-workers noticed that 11 was racemic, because neither 11 nor any of its degradation products showed optical activity

• [112][113][114][115][116], no enantioselective synthesis is available. Full 1H and 13C NMR data of 53 (including 14 carbon signals) have been published [113]. The guaiane sesquiterpenes that are potentially derived from cationic intermediates L1–L4 are summarised in Scheme 16A. trans-β-Guaiene (54) can

• planar structure of 56 was concluded by Pliva and Šorm [128]. After the absolute configuration of 61 was solved [129], the full stereostructure of 56 became known. No total synthesis and no NMR data are available for 56. β-Guaiene is one of the main constituents of the essential oil from Achillea

Sequential hydrozirconation/Pd-catalyzed cross coupling of acyl chlorides towards conjugated (2E,4E)-dienones

• Benedikt Kolb,
• Daniela Silva dos Santos,
• Sanja Krause,
• Anna Zens and
• Sabine Laschat

Beilstein J. Org. Chem. 2023, 19, 176–185, doi:10.3762/bjoc.19.17

• Benedikt Kolb Daniela Silva dos Santos Sanja Krause Anna Zens Sabine Laschat Institut für Organische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany 10.3762/bjoc.19.17 Abstract Dienones are challenging building blocks in natural product synthesis due to their high

• reactivity and complex synthesis. Based on previous work and own initial results, a new stereospecific sequential hydrozirconation/Pd-catalyzed acylation of enynes with acyl chlorides towards conjugated (2E,4E)-dienones is reported. We investigated a number of substrates with different alkyl and aryl

• from a haliclona marine sponge [4], and vertinolide (5) from Verticillium intertextum [5] (Scheme 1). As outlined in Scheme 2, a variety of methods has been reported for the synthesis of conjugated dienones, mostly via addition/elimination reactions such as Knoevenagel condensation or Claisen–Schmidt

Identification and determination of the absolute configuration of amorph-4-en-10β-ol, a cadinol-type sesquiterpene from the scent glands of the African reed frog Hyperolius cinnamomeoventris

• Angelique Ladwig,
• Markus Kroll and
• Stefan Schulz

Beilstein J. Org. Chem. 2023, 19, 167–175, doi:10.3762/bjoc.19.16

• amorph-4-ene-10β-ol known from plants. A short synthesis using an organocatalytic approach through a tandem Mannich/intramolecular Diels–Alder reaction led to a mixture of cadinols, which was used for the assignment of the natural cadinol structures and their stereoisomers. Keywords: Anura; chiral gas

• chromatography; enantioselective synthesis; GC/MS; semiochemicals; Introduction Hyperolius cinnamomeoventris (Figure 1) is one of the largest species of reed frogs (Hyperoliidae), which are commonly found in Africa, south of the Sahara. Males of the Hyperoliidae possess a characteristic yellow gular patch on

• indices and microderivatization of extracts finally lead to structural proposals that have to be verified by synthesis. On this way a large variety of hyperolid and mantellid frog gland constituents have been identified [3][4][5][6][7][8][9]. Herein, we report on the structural elucidation of

Total synthesis of insect sex pheromones: recent improvements based on iron-mediated cross-coupling chemistry

• Eric Gayon,
• Guillaume Lefèvre,
• Olivier Guerret,
• Adrien Tintar and
• Pablo Chourreu

Beilstein J. Org. Chem. 2023, 19, 158–166, doi:10.3762/bjoc.19.15

• insect sex pheromones as an alternative to conventional pesticides is in constant growth. In this report, we discuss the recent contributions brought by our groups in the field of iron-catalyzed cross-couplings applied to the synthesis of insect pheromones. The pivotal question of the development of

• their reproduction and then limit their proliferation, finally lowering the damages caused by pests to the crops. Moreover, those molecules are totally biodegradable, harmless to Humans and don’t interact with non-targeted insects [6]. However, at this time, few pathways for the synthesis of insect

• pheromones reported in the literature are applicable on an industrial scale, which slows the widespread application of this solution. As a matter of fact, the key step of the synthesis of such compounds, which is the introduction of C=C unsaturations, traditionally involves expensive, toxic and low atom

Nostochopcerol, a new antibacterial monoacylglycerol from the edible cyanobacterium Nostochopsis lobatus

• Naoya Oku,
• Saki Hayashi,
• Yuji Yamaguchi,
• Hiroyuki Takenaka and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2023, 19, 133–138, doi:10.3762/bjoc.19.13

• and the concentration at which the growth of microbes was completely inhibited was defined as the minimum inhibitory concentration (MIC). Structure of nostochopcerol (1) and selected COSY (bold lines) and HMBC (arrows) correlations. Synthesis of 1-linoleoyl-sn-glycerol (3a) and 3-linoleoyl-sn-glycerol

• (3b). 1H (500 MHz) and 13C (125 MHz) NMR data for nostochopcerol (1) in CD3OH (δ in ppm). Antimicrobial activity of nostochopcerol (1) and synthetic analogs. Supporting Information Supporting information features procedures for synthesis of chiral α-linoleoyl glycerols, physicochemical properties of

1,4-Dithianes: attractive C2-building blocks for the synthesis of complex molecular architectures

• Bram Ryckaert,
• Ellen Demeyere,
• Frederick Degroote,
• Hilde Janssens and
• Johan M. Winne

Beilstein J. Org. Chem. 2023, 19, 115–132, doi:10.3762/bjoc.19.12

• derivatives thereof at various oxidation states. The selected examples show how the specific heterocyclic reactivity can be harnessed for the controlled synthesis of carbon–carbon bonds. The reactivity is compared to and put into context with more common synthetic building blocks, such as 1,3-dithianes and

• and carbohydrates to various carbocyclic scaffolds. This versatility arises from the possibility to chemoselectively cleave or reduce the sulfur-heterocycle to reveal a versatile C2-synthon. Keywords: 1,4-dithianes; 1,4-dithiins; 2,3-dihydro-1,4-dithiins; heterocycles; target synthesis; Introduction

• 1,3-Dithianes are text book examples of versatile organic synthesis building blocks. They are familiar carbonyl protecting groups, but are more commonly known as ‘umpolung’ reagents, or acyl anion equivalents [1][2][3][4][5][6]. This is because they can be readily metalated and alkylated, allowing the

Synthesis and characterisation of new antimalarial fluorinated triazolopyrazine compounds

• Kah Yean Lum,
• Jonathan M. White,
• Daniel J. G. Johnson,
• Vicky M. Avery and
• Rohan A. Davis

Beilstein J. Org. Chem. 2023, 19, 107–114, doi:10.3762/bjoc.19.11

• lead compounds without the need for de novo synthesis [5]. Baran et al. has developed an operationally simple, radical-based functionalisation strategy that allows direct transformation of C–H bonds to C–C bonds in a practical manner [11]. This strategy involves the utilisation of sodium and zinc

• of the known OSM leads 4–6 was subsequently substituted with three different fluoroalkyl moieties using Diversinate™ chemistry that resulted in the synthesis of nine new fluorinated triazolopyrazines (10–19). The antimalarial data indicated that substitution of H-8 of ether-linked triazolopyrazines

• ), 145.0 (C-5), 146.2 (C-3); LRESIMS m/z: 392 [M + H]+, 414 [M + Na]+, 805 [2M + Na]+; HRESIMS (m/z): [M + H]+ calcd for C21H16F2N5O, 392.1317; found, 392.1317. Key HMBC, COSY and ROESY correlations, and ORTEP drawing of 18. Synthesis of ether triazolopyrazine derivatives 4–9. Synthesis of fluorinated

Practical synthesis of isocoumarins via Rh(III)-catalyzed C–H activation/annulation cascade

• Qian-Ci Gao,
• Yi-Fei Li,
• Jun Xuan and
• Xiao-Qiang Hu

Beilstein J. Org. Chem. 2023, 19, 100–106, doi:10.3762/bjoc.19.10

• activation/annulation cascade of readily available enaminones with iodonium ylides towards the convenient synthesis of isocoumarins. This coupling system proceeds in useful chemical yields (up to 93%) via a cascade C–H activation, Rh-carbenoid migratory insertion and acid-promoted intramolecular annulation

• for the synthesis of isocoumarin scaffolds. Traditional synthetic strategies including 1) intramolecular cyclization of 2-alkenyl benzoic acids or o‑alkynylbenzoates (Scheme 1b, I) [6][7][8][9][10], 2) oxidation of isochromans (Scheme 1b, II) [11][12], or 3) metal-catalyzed cross-coupling/cyclization

• easily available, which have been established as versatile synthetic building blocks for the synthesis of cyclic scaffolds [25]. In 2016, Zhu et al. reported the first example of a Rh-catalyzed C–H functionalization of enaminones with alkynes and α-diazo-β-ketoesters to access naphthalenes [26]. Very

Revisiting the bromination of 3β-hydroxycholest-5-ene with CBr₄/PPh₃ and the subsequent azidolysis of the resulting bromide, disparity in stereochemical behavior

• Christian Schumacher,
• Jas S. Ward,
• Kari Rissanen,
• Carsten Bolm and
• Mohamed Ramadan El Sayed Aly

Beilstein J. Org. Chem. 2023, 19, 91–99, doi:10.3762/bjoc.19.9

• ] showed a good cytotoxic effect against the prostate cancer cell line PC-3 (Figure 2). When the spacer of I was increased from C6 to C11, the antimicrobial potential dramatically decreased [11]. In order to extend the compound platform, the synthesis of 3-azidocholest-5-ene was addressed [10]. Starting

Organophosphorus chemistry: from model to application

• György Keglevich

Beilstein J. Org. Chem. 2023, 19, 89–90, doi:10.3762/bjoc.19.8

• . elaborated a Lewis acid-catalyzed one-pot synthesis of phosphinates and phosphonates staring from pyridinecarboxaldehydes and diarylphosphine oxides [2]. This protocol is the analogy of the Pudovik reaction, followed by the phospha-Brook rearrangement applied mainly for the synthesis of phosphoric ester

• derivatives. In another study, the synthesis of bis(chlorophenyl)acetylenes that were useful for the preparation of 1,2,3-tris(chlorophenyl)cyclopropenylium bromides was accomplished [3]. The latter species were converted to tributyl(1,2,3-tris(chlorophenyl)cyclopropenyl)phosphonium bromides, affording 3,4,5

• -tris(chlorophenyl)-1,2-diphosphacyclopentadienides upon reaction with polyphosphides. These ligands were converted to the corresponding ferrocene complexes. This synthesis was elaborated by Zagidullin and his team. The two remaining articles also indicate the importance of the P-heterocyclic discipline

Preparation of β-cyclodextrin/polysaccharide foams using saponin

• Max Petitjean and
• José Ramón Isasi

Beilstein J. Org. Chem. 2023, 19, 78–88, doi:10.3762/bjoc.19.7

• polysaccharides. Xanthan gum, locust bean gum or chitosan can be crosslinked using citric acid in the presence of β-cyclodextrin to produce insoluble matrices. In this work, polymeric foams based on those polysaccharides and saponin have been prepared using a green synthesis method to increase the porosity of the

• matrices. The saponin of soapbark (Quillaja saponaria) has been used to obtain foams using different procedures. The influence of the synthesis path on the porosity of the materials and their corresponding sorption capacities in the aqueous phase were evaluated. Keywords: chitosan; cyclodextrin polymers

• ; green synthesis; locust bean gum; saponin; sorption; xanthan gum; Introduction Saponins are a family of natural molecules consisting of a hydrophobic aglycone backbone grafted with hydrophilic sugar molecules, allowing the plant to be protected from illnesses [1] and from herbivores endangerment [2

Catalytic aza-Nazarov cyclization reactions to access α-methylene-γ-lactam heterocycles

• Bilge Banu Yagci,
• Selin Ezgi Donmez,
• Onur Şahin and
• Yunus Emre Türkmen

Beilstein J. Org. Chem. 2023, 19, 66–77, doi:10.3762/bjoc.19.6

• reactions constitutes one of the main pillars of organic synthesis [1]. In this respect, the all-carbon Nazarov cyclization of divinyl ketones represents a direct method for the synthesis of five-membered carbocycles [2][3][4][5][6][7][8][9]. Variants of the Nazarov cyclization with substrates bearing one

• the synthesis of tricyclic α-methylene-γ-lactams 7 as single diastereomers and in good to high yields through the use of a catalytic amount of AgOTf (silver trifluoromethanesulfonate) as an anion-exchange agent (Scheme 1d) [35]. In this transformation, treatment of 3,4-dihydroisoquinolines 5 with acyl

• , were obtained as single diastereomers. In order to assess the scalability of the aza-Nazarov cyclization, we investigated the synthesis of the previously unreported lactam 7c via the reaction between imine 5b and acyl chloride 6b on a gram scale (Scheme 2). Acyl chloride 6b was prepared in four steps

NaI/PPh₃-catalyzed visible-light-mediated decarboxylative radical cascade cyclization of N-arylacrylamides for the efficient synthesis of quaternary oxindoles

• Dan Liu,
• Yue Zhao and
• Frederic W. Patureau

Beilstein J. Org. Chem. 2023, 19, 57–65, doi:10.3762/bjoc.19.5

• /cyclization cascades from acrylamides for the synthesis of oxindoles [39][40][41]. The radicals are typically generated from alkyl halides [42][43][44], carboxylic acids [45][46][47], simple alkanes [48], alkylboronic acids [49], isocyanides [50], or other [51][52][53]. In this context, the group of Fu

• reported a Ru(bpy)3Cl2-catalyzed synthesis of N-Boc proline oxindole derivatives under visible-light assistance [47]. Therein, N-hydroxyphthalimide (NPhth) esters were utilized as alkyl radical precursors, which can be readily prepared from highly available carboxylic acids. In 2015, Cheng and co-workers

• advantage of circumventing the need for external redox additives and/or noble metals, using readily available and cost-effective NaI and PPh3 under mild reaction conditions. In a broader context, phosphine organocatalysis is probably still underappreciated in organic synthesis, and could lead to important

Modern flow chemistry – prospect and advantage

• Philipp Heretsch

Beilstein J. Org. Chem. 2023, 19, 33–35, doi:10.3762/bjoc.19.3

• natural product synthesis programs [3], has revealed some inadequacies, particularly in view of the equipment and procedures available. These limitations have been slowly overcome with many creative but sometimes highly “academic” solutions. Thus, recent years witnessed a steady increase in the

• into one another [11]. This concept has been adapted and further refined by Gilmore and co-workers, introducing automated multistep synthesizers [12], as well as Heretsch et al. in a setup optimized for natural products synthesis and late-stage manipulations [13]. To address customized reactor

• typically call for an optimized or even specifically designed reactor built, the modularity of flow reactor is vital for quick reconfiguration and switching between different reactions. This argument is particularly true when natural product synthesis is to be performed in continuous flow. The need for

Two-step continuous-flow synthesis of 6-membered cyclic iodonium salts via anodic oxidation

• Julian Spils,
• Thomas Wirth and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2023, 19, 27–32, doi:10.3762/bjoc.19.2

• blocks for the synthesis of natural products [16][17][18][19][20][21]. One subclass of HVIs is diaryliodonium salts (DIS), which have been used as versatile electrophilic arylation reagents in metal-catalyzed and metal-free reactions [22][23]. The corresponding cyclic diaryliodonium salts (CDIS) have

• also been investigated as useful building blocks for the synthesis of larger diaryl-based molecules, (hetero)aromatic tricyclic systems, or new aryl-moieties [24][25]. Most methods that generate DIS utilize iodoarenes as starting materials [26][27]. In these one-pot procedures, iodoarenes react with

• nucleophilic arenes under oxidative acidic conditions.The synthesis of CDIS is more challenging since the arene moiety must be covalently connected to the iodoarene prior to cyclization. Recently, we published two new methods that describe the generation of carbon- and heteroatom-bridged CDIS [28][29]. Herein

Combining the best of both worlds: radical-based divergent total synthesis

• Kyriaki Gennaiou,
• Antonios Kelesidis,
• Maria Kourgiantaki and
• Alexandros L. Zografos

Beilstein J. Org. Chem. 2023, 19, 1–26, doi:10.3762/bjoc.19.1

• Kyriaki Gennaiou Antonios Kelesidis Maria Kourgiantaki Alexandros L. Zografos Aristotle University of Thessaloniki, Department of Chemistry, Laboratory of Organic Chemistry, Thessaloniki, 54124, Greece 10.3762/bjoc.19.1 Abstract A mature science, combining the art of the total synthesis of

• of atom economy and protecting-group-free synthesis dominating the field of total synthesis. In this new era, total synthesis is moving towards natural efficacy by utilizing both the biosynthetic knowledge of divergent synthesis and the latest developments in radical chemistry. This contemporary

• review highlights recent total syntheses that incorporate the best of both worlds. Keywords: biomimetic synthesis; cascades; common scaffold; hydrogen atom transfer; photoredox catalysis; Introduction Societal needs push sciences into new directions, as the urge for new pharmaceutical leads grows, in

Digyalipopeptide A, an antiparasitic cyclic peptide from the Ghanaian Bacillus sp. strain DE2B

• Adwoa P. Nartey,
• Aboagye K. Dofuor,
• Kofi B. A. Owusu,
• Anil S. Camas,
• Hai Deng,
• Marcel Jaspars and
• Kwaku Kyeremeh

Beilstein J. Org. Chem. 2022, 18, 1763–1771, doi:10.3762/bjoc.18.185

• novo total synthesis or degradation. This is because in natural product peptides both the ᴅ- and ʟ-forms of the different amino acids may be incorporated into the peptide structure. In order to determine the regiochemistry of the Val, Leu, Asp, and Glu amino acid residues in compound 1, we deployed the

Synthetic study toward tridachiapyrone B

• Morgan Cormier,
• Florian Hernvann and
• Michaël De Paolis

Beilstein J. Org. Chem. 2022, 18, 1741–1748, doi:10.3762/bjoc.18.183

• , as illustrated by Baldwin in the synthesis of 9,10-deoxytridachione [18]. In a further demonstration of the versatility of tetraenes connected to α’-methoxy-γ-pyrone, the synthesis of both crispatene and photodeoxytridachione was accomplished by Trauner through the Lewis acid-catalyzed 6π-disrotatory

• synthesis of tridachiapyrone B was not investigated, even though it seems conceivable that the compound’s stability to light, air or cytochrome would be higher than its 1,3-cyclohexadiene counterpart. As the molecule combines electron acceptor functions such as α’-methoxy-γ-pyrone and 2,5-cyclohexadienone

• chain to the 2,5-cyclohexadienone scaffold. Avoiding heat and light sensitive tetraenes, the convergent plan would also give the opportunity to assess an enantioselective synthesis of the targets, noting that the C14 epimeric product, isotridachiapyrone B, has also been isolated by Schmitz. Results and

Inline purification in continuous flow synthesis – opportunities and challenges

• Jorge García-Lacuna and
• Marcus Baumann

Beilstein J. Org. Chem. 2022, 18, 1720–1740, doi:10.3762/bjoc.18.182

• chemistry tools developed in academia. Keywords: flow synthesis; inline purification; process development; reaction telescoping; scale-up; Introduction Continuous flow chemistry is a mature and widely applied platform technology that exploits intrinsic advantages over batch processing such as better heat

• mode synthesis [3][4][5]. Reactor miniaturization thereby renders many benefits including better control over mixing and heat transfer, whilst offering cost effective small footprint setups with a high degree of modularity. Researchers can choose from creating custom-built flow setups that offer

• two columns respectively. Automatically, the systems run different methods for sample separation, alternating columns so that one is engaged with the chromatography method while the other is being loaded. Depending on the synthesis flow rate and method duration, the injected volume of crude mixture