Melifoliox B, a novel phloroglucin derivative isolated from Melicope barbigera (Rutaceae) and synthesis of new oxidation products from melifoliones A and B

• Horst Weber,
• Kim-Thao Tran-Cong,
• Bernhard Mayer,
• Guido J. Reiss,
• Iryna S. Konovalova,
• Marc S. Appelhans,
• Kenneth R. Wood and
• Claus M. Passreiter

Beilstein J. Org. Chem. 2026, 22, 535–546, doi:10.3762/bjoc.22.39

• from mixtures of melifoliones 1 and 2 using the applied chemical methods. Thus, it is clearly proven, that 4 cannot be built as an artifact during the isolation. Therefore, it is likely that the biosynthesis of the quinol 4 occurs via enzymatically catalysed oxidation in the leaves of Melicope

• reagents were of analytical grade. Melting points were determined on a Büchi SMP 20. Microwave experiments were performed in sealed tubes on a CEM, model DISCOVER, power 300 Watt apparatus with a special temperature programme. Isolation of compound 4 Compound 4 was isolated from the VLC-fraction MB-IX-5-P1

Modern synthetic pathways towards eribulin and its subunits

• Sebastian Dominik Graf

Beilstein J. Org. Chem. 2026, 22, 495–526, doi:10.3762/bjoc.22.37

• within their isolation study on halichondrin B, in 1986, Hirata and Uemura showed its promising activity against murine cancer cells [6], which led to a great interest in the pharmaceutical society [7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Only 6 years later, Kishi and co-workers first

• of 1, its rapid development from first total synthesis to large scale production also highlights advances in the realm of synthetic chemistry. This progress was indispensable to ensure today`s broad accessibility, since only smallest quantities would be obtainable through isolation form its natural

Dialkylaminoalkylation of β-ketosulfones via ring-opening of 3-sulfonylpyrrolidines

• Evgeny M. Buev,
• Alexander V. Pavlushin,
• Vladimir S. Moshkin and
• Vyacheslav Y. Sosnovskikh

Beilstein J. Org. Chem. 2026, 22, 383–389, doi:10.3762/bjoc.22.26

• by adding the alkyl halide directly to the cooled reaction mixture of the formed pyrrolidine without its isolation and purification, that provided higher yields of the quaternary compounds 3 rather than step by step approach. Further, we focused our attention on the search for the reaction conditions

• -amine (5) in 77% yield (Scheme 4). This observation prompted us to examine methoxy and morpholine adducts 4a and 4o in the same process that resulted in the isolation of sulfonylamine 5 in 69 and 48%, respectively. The literature search revealed that previously Langler and co-authors observed the

Ring contraction and ring expansion reactions in terpenoid biosynthesis and their application to total synthesis

• Nicolas Kratena,
• Nicolas Heinzig and
• Peter Gärtner

Beilstein J. Org. Chem. 2026, 22, 289–343, doi:10.3762/bjoc.22.21

• editing; terpenoids; total synthesis; Introduction The vast richness of structural diversity in terpenoid natural products has fascinated organic chemists for more than a century now [1][2][3][4][5]. With more sophisticated techniques for isolation and characterisation emerging over the decades

• , thousands of closely related compounds could be identified. Among these, the more structurally interesting, rearranged or highly oxidised members can often only be vaguely traced back to their biogenetic origin based on co-isolation and biochemical intuition. Synthetic approaches can sometimes help to solve

• crokonoid B (67) by oxidation, carbocation formation and 1,2-alkyl shift in a semi-pinacol rearrangement [127]. The authors of the isolation report proposed an epoxide 67a as initiating species, but a diol could also serve in this function (see Scheme 21B). Upon formation of the secondary carbocation 67b, a

Spirobarbiturates with a pyrrolizidine moiety: synthesis, structure and biological evaluation

• Arthur A. Puzyrkov,
• Andrew S. Drachuk,
• Ekaterina A. Popova,
• Alexander V. Stepakov and
• Vitali M. Boitsov

Beilstein J. Org. Chem. 2026, 22, 274–288, doi:10.3762/bjoc.22.20

• mixture by preparative TLC or column chromatography. Notably, compounds 4a, 4e, and 4k were purified by crystallization. Detailed synthetic and isolation procedures for all compounds are provided in Supporting Information File 1. We regret to state that when forming a mixture of diastereomers, we were

Arene activation via π-bond localization: concepts and opportunities

• Paul Meiners,
• Julian J. Melder and
• Tobias Morack

Beilstein J. Org. Chem. 2026, 22, 257–273, doi:10.3762/bjoc.22.19

• ; Introduction Aromaticity has intrigued chemists since Michael Faraday’s isolation of benzene in 1825, marking the beginning of a concept that has shaped much of modern chemical thinking [1][2]. Despite its fundamental importance, aromaticity remains an abstract notion [3]. It is central to understanding

• Taube reported the now famous pentaammineosmium(II) η2-benzene complex: the first system to yield kinetically stable η2-arene complexes that resist ligand exchange at room temperature in solution (Figure 5) [48]. This breakthrough opened the door to the isolation of such complexes and their subsequent

A mild and atom-efficient four-component cascade strategy for the construction of biologically relevant 4-hydroxyquinolin-2(1H)-one derivatives

• Dmitrii A. Grishin,
• Kseniia I. Sharkovskaia,
• Ilya G. Kolmakov,
• Daria A. Ipatova,
• Rostislav A. Petrov,
• Nikolai D. Dagaev,
• Dmitry A. Skvortsov,
• Maria G. Khrenova,
• Valeriy V. Andreychev,
• Sergei A. Evteev,
• Yan A. Ivanenkov,
• Roman L. Antipin,
• Olga А. Dontsova and
• Elena K. Beloglazkina

Beilstein J. Org. Chem. 2026, 22, 244–256, doi:10.3762/bjoc.22.18

• quantitatively. Although the two-step sequence generally performed well, isolation of malonamides 1a–c was associated with significant material loss, impacting the overall yield. To address this, a one-pot synthesis directly from anilines was developed, avoiding isolation of intermediates. After approximately 4

• esterification of acids 11a–c afforded the isopropyl esters 12a–c in 71–98% yields. Similar attempts were made using cyclohexyl alcohol both as reagent and solvent in Fischer–Speier esterification; however, difficulties in purifying the reaction mixtures due to the large excess of alcohol prevented isolation of

• efficient reaction progress and facile isolation of pure products, with yields ranging from 65 to 81%. Pyranoquinolines 14a–c can be prepared from acids 11a–c via Fischer–Speier esterification, Steglich esterification, or intramolecular acylation through in situ formation of acyl chlorides. The cyclic

Synthesis of diaryl phosphates using phytic acid as a phosphorus source

• Kazuya Asao,
• Seika Matsumoto,
• Haruka Mori,
• Riku Yoshimura,
• Takeshi Sasaki,
• Naoya Hirata,
• Yasuyuki Hayakawa and
• Shin-ichi Kawaguchi

Beilstein J. Org. Chem. 2026, 22, 213–223, doi:10.3762/bjoc.22.15

• would be difficult. Furthermore, when 1-naphthol (1k) and 2-naphthol (1l) were used as substrates, the 31P NMR yields of the produced diesters were 45% (2k) and 29% (2l), respectively, and their isolation was difficult because of the presence of large amounts of naphthol-derived by-products. When the

• diaryl phosphate was isolated as a sodium salt, and the isolated yields are listed below. The yields in parentheses represent 31P nuclear magnetic resonance (NMR) yields defined based on a calibration curve using triphenylphosphine oxide as an internal standard. The isolation of 2c and 2j was not

Streptoquinolines A and B, new antibacterial meroterpenoids produced by Streptomyces sp. TMPU-A0679

• Akiho Yagi,
• Hitomi Tomura,
• Ami Konno and
• Ryuji Uchida

Beilstein J. Org. Chem. 2026, 22, 185–191, doi:10.3762/bjoc.22.12

• B (2) (Figure 1). Compounds 1 and 2 possessed a unique skeleton consisting of a drimane-type sesquiterpene fused with a quinoline moiety and both exhibited potent antibacterial activity against Gram-positive bacteria. This study describes the production, isolation, structural elucidation, and

• (Iwashiya Bio Science, Tokyo, Japan) at 180 rpm at 27 °C for 7 days. Isolation of compounds 1 and 2 The culture broth (6.0 L) was centrifuged to separate the mycelia and supernatant. Collected mycelia were treated with acetone (1.0 L) for 60 minutes. After suction filtration, the acetone solution was

Highly electrophilic, gem- and spiro-activated trichloromethylnitrocyclopropanes: synthesis and structure

• Ilia A. Pilipenko,
• Mikhail V. Grigoriev,
• Olga Yu. Ozerova,
• Igor A. Litvinov,
• Darya V. Spiridonova,
• Aleksander V. Vasilyev and
• Sergey V. Makarenko

Beilstein J. Org. Chem. 2026, 22, 123–130, doi:10.3762/bjoc.22.5

• were obtained using a MaXis mass spectrometer (Bruker Daltonik GmbH) equipped with an electrospray ionization source (4.5 eV) and a quadrupole time-of-flight analyzer (ESI–QTOF) in the positive ions detection mode, with methanol (0.1% FA [formic acid]) as solvent. Isolation of individual diastereomers

Total synthesis of natural products based on hydrogenation of aromatic rings

• Haoxiang Wu and
• Xiangbing Qi

Beilstein J. Org. Chem. 2026, 22, 88–122, doi:10.3762/bjoc.22.4

• functional group manipulations, including a pivotal intramolecular SN2 cyclization, ultimately completing the total synthesis of (−)-senepodine F. Notably, this work also led to the structural revision of the originally assigned natural product, as reported in earlier isolation studies. Hydrogenation

Synthesis and applications of alkenyl chlorides (vinyl chlorides): a review

• Daniel S. Müller

Beilstein J. Org. Chem. 2026, 22, 1–63, doi:10.3762/bjoc.22.1

One-pot synthesis of ethylmaltol from maltol

• Immanuel Plangger,
• Marcel Jenny,
• Gregor Plangger and
• Thomas Magauer

Beilstein J. Org. Chem. 2025, 21, 2755–2760, doi:10.3762/bjoc.21.212

• , needles, and bark of certain trees. In particular, the bark of larch trees contains 0.1–2 wt % maltol (2) and economic isolation methods using for example aqueous tannin liquors with extraction efficiencies of >90% have been developed [22][23][24]. Owing to the natural availability of maltol (2

Total synthesis of asperdinones B, C, D, E and terezine D

• Ravi Devarajappa and
• Stephen Hanessian

Beilstein J. Org. Chem. 2025, 21, 2730–2738, doi:10.3762/bjoc.21.210

• activity [20]. A related metabolite lacking the C7 prenyl group had been isolated from the cultures of Aspergillus chevalieri in 1976 [21]. The structure and absolute stereochemistry were confirmed by synthesis from tryptophan and ʟ-alanine [22]. The isolation of terezine D (6) and more recently, the (3R

Recent advancements in the synthesis of Veratrum alkaloids

• Morwenna Mögel,
• David Berger and
• Philipp Heretsch

Beilstein J. Org. Chem. 2025, 21, 2657–2693, doi:10.3762/bjoc.21.206

• subclass The cevanine-type alkaloids constitute the largest of the three subgroups of Veratrum alkaloids. However, they have long withstood the efforts of total synthesis endeavors, perhaps owing to their typically densely functionalized hexacyclic framework. To date, the isolation of at least 80 different

• isolation of heilonine was reported in 1989 by Kaneko et al. from Fritillaria ussuriensis. It is believed to be a constituent of “beimu", a traditional Chinese medicine that is used as a sedative, antitussive, and expectorant [52]. The nine stereocenters reside in two different regions of the molecule

Thiazolidinones: novel insights from microwave synthesis, computational studies, and potentially bioactive hybrids

• Luan A. Martinho,
• Victor H. J. G. Praciano,
• Guilherme D. R. Matos,
• Claudia C. Gatto and
• Carlos Kleber Z. Andrade

Beilstein J. Org. Chem. 2025, 21, 2618–2636, doi:10.3762/bjoc.21.203

• ), delivers excellent yields (up to 99%), and requires a low catalyst loading (10 mol %). The reactions are fast and can be applied to a wide range of aromatic and heteroaromatic aldehydes, with product isolation achieved by the simple addition of an aqueous HCl solution. This methodology was successfully

Efficient solid-phase synthesis and structural characterization of segetalins A–H, J and K

• Liangyu Liu,
• Wanqiu Lu,
• Quanping Guo and
• Zhaoqing Xu

Beilstein J. Org. Chem. 2025, 21, 2612–2617, doi:10.3762/bjoc.21.202

• , culminating in cyclization mediated by N,N'-dicyclohexylcarbodiimide (DCC)/N-methylmorpholine (NMM) at 0 °C for 7 days [18]. This method, however, is lengthy, operationally complex, difficult for product isolation, and carries a significant risk of racemization. Wong and Jolliffe synthesized segetalins B (2

Recent advances in total synthesis of illisimonin A

• Juan Huang and
• Ming Yang

Beilstein J. Org. Chem. 2025, 21, 2571–2583, doi:10.3762/bjoc.21.199

• embellished by additional bridging via a γ-lactone and a γ-lactol ring, resulting in a caged pentacyclic scaffold with a 5/5/5/5/5 ring arrangement. The compound demonstrates neuroprotective activity by mitigating oxygen-glucose deprivation-induced cell injury in SH-SY5Y cells. Since its isolation in 2017

• , illisimonin A has garnered significant interest from the synthetic chemistry community. To date, five research groups have accomplished the total synthesis of illisimonin A. This review offers a comprehensive overview of its isolation, proposed biosynthetic pathway and the synthetic strategies employed in its

• have been isolated from this genus, among which Illicium sesquiterpenes represent a prominent group. Since the first isolation of anisatin in 1952 [1], more than 100 Illicium sesquiterpenes have been isolated from over 40 species of Illicium [2]. Based on their carbon skeletons, they can be classified

Total syntheses of highly oxidative Ryania diterpenoids facilitated by innovations in synthetic strategies

• Zhi-Qi Cao,
• Jin-Bao Qiao and
• Yu-Ming Zhao

Beilstein J. Org. Chem. 2025, 21, 2553–2570, doi:10.3762/bjoc.21.198

• ]. Research on these compounds dates back to 1943 when the American pharmaceutical company Merck developed a novel insecticide, Ryanex, from the stems and leaves of the plant. In 1948, Folkers and colleagues reported the isolation of the first bioactive member of this family – ryanodine (1) [8]. Due to

• scaffold yet exhibit diverse oxidation patterns and stereochemical configurations, with ryanodine (1) representing a landmark example (Table 1). This review has highlighted synthetic investigations of Ryania diterpenoids by various research groups, encompassing brief discussions of their isolation

Assembly strategy for thieno[3,2-b]thiophenes via a disulfide intermediate derived from 3-nitrothiophene-2,5-dicarboxylate

• Roman A. Irgashev

Beilstein J. Org. Chem. 2025, 21, 2489–2497, doi:10.3762/bjoc.21.191

• isolation of compounds 2 and 3 in analytically pure form allowed their structure to be established thanks to elemental analysis and HRMS. It was found that compounds 2 and 3 are dimeric derivatives of the starting thiophene, linked by sulfur bridges located at the C-3 position instead of the nitro group

Transformation of the cyclohexane ring to the cyclopentane fragment of biologically active compounds

• Natalya Akhmetdinova,
• Ilgiz Biktagirov and
• Liliya Kh. Faizullina

Beilstein J. Org. Chem. 2025, 21, 2416–2446, doi:10.3762/bjoc.21.185

• KMnO4 in EtOH at 0 °C afforded vicinal diol 20 with a yield of 58%. The periodate cleavage of the latter under the action of NaIO4 led to the formation of a labile dialdehyde, which was treated with t-BuOK in THF without isolation. As a result of intramolecular aldol condensation, accompanied by the

• led to the isolation of alcohol 138 with a yield of 52%. The Wolff rearrangement was carried out upon irradiation of a solution of mesylate 139 in THF at 25 °C with a medium-pressure Hg lamp for 1 hour. The ring contraction proceeded diastereoselectively and the desired acid 140 was obtained as a

• 10 μg/mL). Sequential interaction of indole 219 with pyridinium p-toluenesulfonate (PPTS) and excess of Davis’ oxaziridine 222, an effective oxidizing agent for synthesis of spirooxindole alkaloids, led to epoxide 220. Labile oxirane 220, without isolation, was subjected to a semipinacol

The high potential of methyl laurate as a recyclable competitor to conventional toxic solvents in [3 + 2] cycloaddition reactions

• Ayhan Yıldırım and
• Mustafa Göker

Beilstein J. Org. Chem. 2025, 21, 2389–2415, doi:10.3762/bjoc.21.184

• solvent medium for the reaction, and the related compounds were obtained through straightforward isolation techniques in a relatively short time frame (5–80 minutes). A comprehensive investigation was conducted utilizing various web platforms, encompassing ecological and environmental risk assessments

• a promising biocompatible solvent alternative in numerous chemical transformations, there are several challenges associated with product isolation that must be addressed [23]. Consequently, it is evident that the endeavor to identify an optimal green solvent for both industrial and academic

• in the isolation of the cycloadduct through precipitation, given that castor oil is insoluble in hexane. The solvent dissolves the product together with castor oil, causing it to pass to the filtrate phase and thereby reducing the amount present. In order to remain faithful to the principles of Green

Rotaxanes with integrated photoswitches: design principles, functional behavior, and emerging applications

• Jullyane Emi Matsushima,
• Khushbu,
• Zuliah Abdulsalam,
• Udyogi Navodya Kulathilaka Conthagamage and
• Víctor García-López

Beilstein J. Org. Chem. 2025, 21, 2345–2366, doi:10.3762/bjoc.21.179

• property, in addition to facilitating their study and isolation, is advantageous for various applications. The first stiff-stilbene-based rotaxane was reported in 2018 [79]. This [1]rotaxane used stiff-stilbene as one of the stoppers, and its photoisomerization produced the translation of a pillar[5]arene

Comparative analysis of complanadine A total syntheses

• Reem Al-Ahmad and
• Mingji Dai

Beilstein J. Org. Chem. 2025, 21, 2334–2344, doi:10.3762/bjoc.21.178

• produce 11, which could be further converted to 12 and 13 for an intermolecular Mannich-type dimerization to form the C2–C3’ linkage [13]. Further oxidation state adjustment would give complanadines A, B, D, and E. Since their isolation, the complanadines, especially complanadine A, have attracted a

Recent advances in Norrish–Yang cyclization and dicarbonyl photoredox reactions for natural product synthesis

• Peng-Xi Luo,
• Jin-Xuan Yang,
• Shao-Min Fu and
• Bo Liu

Beilstein J. Org. Chem. 2025, 21, 2315–2333, doi:10.3762/bjoc.21.177

• economy of "one precursor for multiple targets", and provides a valuable scheme for building structurally diverse natural product libraries. 1.4 Gracilisoids A–I In 2025, Li's group exemplified the “Isolation-Synthesis-Functionality” research concept for a new class of sesterterpenoids, namely