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

• , DMAP, NEt3, DCM, rt; ii. NaBr, n-Bu4NBr, acetone, reflux; iii. HFIP, H2O, rt; iv. DMP; (d) i. Me3SnOH, DCE, 80–85 °C, then 0.1 M HCl; ii. EtSH, DCC, DMAP, DCM, rt; MMTrCl: 4-methoxytriphenylmethyl chloride; Sia2BH: disiamylborane; HFIP: 1,1,1,3,3,3-hexafluoroisopropanol. Synthesis of 1. (a) CrCl2, 37

• °C; (b) Pd(PPh3)4, PPh3, HCOOH, NEt3, THF, 60 °C; (c) i. Mg(OMe)2, THF, MeOH, rt; ii. TBDMSCl, imidazole, DMF, rt. Below: Mechanism of the allene-Prins reaction. Synthesis of 64. Reaction conditions: (a) i. acetone, I2, rt; ii. vinylmagnesium bromide, THF, −20 °C to rt; iii. TsCl, pyridine, 65 °C; (b

• : Reaction conditions: (a) i. K2CO3, MeOH, 60 °C; ii. 2,2-dimethoxypropane, H2SO4 (aq), acetone, rt; (b) i. PMBCl, t-BuOK, TBAI, DMF, THF, rt; ii. OsO4, NaIO4, 2,6-lutidine, 1,4-dioxane, H2O, −20 °C; iii. N-BuLi, furan, THF, 0 °C; (c) i. (PhO)3PMeI, dimethylacetamide, rt; ii. AD-mix-α, t-BuOH, H2O, rt; (d) i

Synthesis and uranyl(VI) extraction performance of a calix[4]pyrrole–tetrahydroxamic acid receptor

• Sara Karnib,
• Rana Baydoun,
• Wissam Zaidan,
• Nancy AlHaddad,
• Omar El Samad,
• Bilal Nsouli,
• Francine Cazier-Dennin and
• Pierre-Edouard Danjou

Beilstein J. Org. Chem. 2026, 22, 486–494, doi:10.3762/bjoc.22.36

• mixture of acetonitrile and acetone. Using this protocol, the PCP α,α,α,α-isomer was recovered in 47% yield, as previously reported by Namor and Shehab [49]. Subsequently, the synthesis of the PCP ester derivative (PCP E) was carried out via O-alkylation of PCP with ethyl bromoacetate in dry acetone/K2CO3

Structural reassignment of compound 968, an allosteric glutaminase inhibitor

• Lindsey A. Albertelli,
• Sainabou Jallow,
• Chun Li and
• Scott M. Ulrich

Beilstein J. Org. Chem. 2026, 22, 455–460, doi:10.3762/bjoc.22.33

• , 130.92, 129.02, 128.68, 128.12, 127.49, 124.25, 122.93, 120.88, 118.45, 117.59, 116.53, 107.43, 50.77, 44.22, 35.30, 32.80, 29.56, 27.06. X-ray crystallography Crystals of compound 2 were grown by slow evaporation from a saturated acetone solution. A yellow, multi-faceted block of suitable size (0.362

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

• reactive pathway consists of an alkene isomerisation from the propenyl-substituent at C-5, followed by protonation of the C-7 alcohol to give intermediate 116a. From here a transannular cyclopropanation affords the cation 116b, which upon nucleophilic attack of water provides 116c. Expulsion of acetone

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

• shaker (180 rpm) at 27 °C for 7 days using a malt extract-based production medium. Harvested mycelia (1.0 L) were extracted with acetone and ethyl acetate, and purification was guided by antibacterial activity against VRE. The crude extract (922 mg) was subjected to ODS column chromatography followed by

• acetone; therefore, they may be artifacts that formed via the nucleophilic addition of acetone to a ketone-bearing precursor during the extraction process. Despite various modifications to fermentation conditions, it was not possible to detect or isolate the presumed natural precursor. We are currently

• that 1 and 2 shared the same planar structure and drimane core configuration (5R,8S,9S,10R), but differed in their stereochemistries at C-4', indicating that they are epimers. Based on the presence of an acetone-derived substituent at C-4', these compounds may be artifacts of a ketone-bearing precursor

A new synthesis of Tyrian purple (6,6’-dibromoindigo) and its corresponding sulfonate salts

• Holly Helmers,
• Mark Horton,
• Julie Concepcion,
• Jeffrey Bjorklund and
• Nicholas C. Boaz

Beilstein J. Org. Chem. 2026, 22, 167–174, doi:10.3762/bjoc.22.10

• acetone yields 1 as a dark purple powder in 59% isolated yield. It was also possible to use crude 4 obtained in the previous step (84% by wt) without purification to yield 1 in 56% isolated yield. This yield is similar to others reported for the condensation of 4 to 1 using the Baeyer–Drewson process [7

Symmetrical D–π–A–π–D indanone dyes: a new design for nonlinear optics and cyanide detection

• Ergin Keleş,
• Alberto Barsella,
• Nurgül Seferoğlu,
• Zeynel Seferoğlu and
• Burcu Aydıner

Beilstein J. Org. Chem. 2026, 22, 131–142, doi:10.3762/bjoc.22.6

• spectrometry methods (Figures S1–S10 in Supporting Information File 1). Optical properties of dyes Photophysical properties of dyes 2a–c were assessed in four different organic solvents with various polarities (DMSO, acetone, chloroform, and THF) via absorption spectra and DFT calculations (Table 2). Figure 2a

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

Sustainable electrochemical synthesis of aliphatic nitro-NNO-azoxy compounds employing ammonium dinitramide and their in vitro evaluation as potential nitric oxide donors and fungicides

• Alexander S. Budnikov,
• Nikita E. Leonov,
• Michael S. Klenov,
• Andrey A. Kulikov,
• Igor B. Krylov,
• Timofey A. Kudryashev,
• Aleksandr M. Churakov,
• Alexander O. Terent’ev and
• Vladimir A. Tartakovsky

Beilstein J. Org. Chem. 2025, 21, 2739–2754, doi:10.3762/bjoc.21.211

• ), and ammonium dinitramide (ADN) (1–5 equiv, 1–5 mmol, 62–310 mg) in 10 mL of MeCN, acetone, DMF, MeOH or HFIP was electrolyzed using constant current conditions (I = 15–240 mA) at 23–25 °C under magnetic stirring. After passing 1–3 F∙mol−1 of electricity (reaction time 7–161 min), electrodes were

Competitive cyclization of ethyl trifluoroacetoacetate and methyl ketones with 1,3-diamino-2-propanol into hydrogenated oxazolo- and pyrimido-condensed pyridones

• Svetlana O. Kushch,
• Marina V. Goryaeva,
• Yanina V. Burgart,
• Marina A. Ezhikova,
• Mikhail I. Kodess,
• Pavel A. Slepukhin,
• Alexandrina S. Volobueva,
• Vladimir V. Zarubaev and
• Victor I. Saloutin

Beilstein J. Org. Chem. 2025, 21, 2716–2729, doi:10.3762/bjoc.21.209

• conditions for the reaction of ethyl trifluoroacetoacetate (1) and acetone (2a) with 1,3-diaminopropan-2-ol (3) (Scheme 1). The selection of conditions is necessary, because alternative octahydropyrido[1,2-a]pyrimidin-6-one 4 and hexahydrooxazolo[3,2-a]pyridin-5-one 5 can be formed due to the presence of

• -octahydropyridopyrimidinone 4act to 14% was observed. We succeeded in isolating all six products 4 and 5 from the reaction of ester 1, acetone (2a), amine 3 in dioxane (Scheme 1). Octahydropyrido[1,2-a]pyrimidinones 4act and 4att, which were formed in larger quantities, were the first to be isolated: the bicycle 4act

• ketones 2b,c (Scheme 2), similar to the transformations with acetone 2a (Scheme 1). The conversion and the preparative yields of products 4b,c and 5b,c are given in Table 2. The regioselectivity is the main feature of the reaction of ester 1 and diaminopropanol (3) with acetophenone (2d), because in this

Tandem hydrothiocyanation/cyclization of CF₃-iminopropargyl alcohols with NaSCN in the presence of AcOH

• Ruslan S. Shulgin,
• Ol’ga G. Volostnykh,
• Anton V. Stepanov,
• Igor’ A. Ushakov,
• Alexander V. Vashchenko and
• Olesya A. Shemyakina

Beilstein J. Org. Chem. 2025, 21, 2694–2702, doi:10.3762/bjoc.21.207

• , electron ionization, electron energy: 70 eV, ion source temperature 200 °C; mass range 34–650 Da. The solvent was chloroform or acetone. Column chromatography was performed on silica gel 60 (70–230 mesh, particle size 0.063–0.200 mm or 230–400 mesh, particle size 0.040–0.063 mm, Merck). Commercially

• acetic acid. The reaction was carried out at room temperature and with vigorous stirring for 15 minutes. Next, the solvent was removed and the residue was purified using column chromatography (eluting with diethyl ether/hexane 1:8, then acetone/hexane 2:1 to give products 2 and 3. Procedure for oxidation

• stirring. The reaction mixture was heated in a glycerol bath at 80 °C for 10 h. The solvent was evaporated and the residue was purified by column chromatography (eluting with hexane/acetone 1:1) to obtain the mixture of products 4 and 5. 1H and 19F NMR monitoring of 1a/NaSCN/AcOH (a, b) and 1g/NaSCN/AcOH

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

• formation and reductive coupling with an aldehyde made accessible β-amino alcohol 60 over two steps. A cascade reaction occurred upon treatment with HCl in acetone followed by treatment with KOH. Indeed, a tandem 5-exo-trig cyclization, sulfinyl removal, and lactamization occurred in one-pot. Finally

Synthesis of new tetra- and pentacyclic, methylenedioxy- and ethylenedioxy-substituted derivatives of the dibenzo[c,f][1,2]thiazepine ring system

• Gábor Berecz,
• András Dancsó,
• Mária Tóthné Lauritz,
• Loránd Kiss,
• Gyula Simig and
• Balázs Volk

Beilstein J. Org. Chem. 2025, 21, 2645–2656, doi:10.3762/bjoc.21.205

• (100 mL), the combined organic phases were dried over Na2SO4, evaporated, and the oily residue was triturated with a little amount of acetone to afford a second crop of crude 7 (8.45 g of pale yellow solid). The two crops were purified by dry-column flash chromatography on a short silica gel column

• dissolved in 10 mL of water, containing 6 mmol of HCl). It was stirred at room temperature for 5 h, the solid product obtained was filtered, washed with water (2 × 3 mL), and air-dried. It was dissolved in acetone (20 mL), the solution was treated with charcoal (0.20 g), and evaporated in vacuo. The residue

Silica gel with covalently attached bambusuril macrocycle for dicyanoaurate sorption from water

• Michaela Šusterová and
• Vladimír Šindelář

Beilstein J. Org. Chem. 2025, 21, 2604–2611, doi:10.3762/bjoc.21.201

• toluene, ethanol and acetone to remove unreacted APTES and dried in vacuo (50 °C) overnight in order to get a-SG [15][16]. Further, to prepare covalent SG-NHCO-BU1, a-SG (0.9 g) was suspended in DMF (15 mL) and shaken at ambient temperature for 30 min. BU1 (0.1 g, 1 equiv) was dissolved in a minimum

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

• the nucleophilic substitution of the nitro group in 2-nitrobenzonitriles using Na2S in a DMF/water medium, followed by alkylation of the resulting 2-cyanophenylthiolates and subsequent cyclization [31]. However, in our case, the reaction of ester 1 with Na2S in either acetone or a DMF/water mixture

• to be an unsuitable route for nucleophilic substitution of its nitro group. Next, we explored an alternative route using potassium thioacetate (KSAc) as a softer nucleophile. Unexpectedly, the reaction of ester 1 with KSAc in acetone gave a mixture of products other than the desired 3-AcS-substituted

Insoluble methylene-bridged glycoluril dimers as sequestrants for dyes

• Suvenika Perera,
• Peter Y. Zavalij and
• Lyle Isaacs

Beilstein J. Org. Chem. 2025, 21, 2302–2314, doi:10.3762/bjoc.21.176

• insoluble in water as required for their use as solid state sequestrants. Unlike most acyclic CB[n]-type receptors, G2W1–G2W4 are soluble in organic solvents (G2W1 and G2W2: soluble in CHCl3, CH2Cl2, DMSO, and TFA but insoluble in methanol, acetone, acetonitrile, and hexane; G2W3: soluble in DMSO and TFA

• but insoluble in CHCl3, CH2Cl2, methanol, acetone, acetonitrile, and hexane; G2W4: soluble in CHCl3, CH2Cl2, acetonitrile, DMSO, and TFA but insoluble in methanol, acetone, and hexane). The new hosts G2W1–G2W4 were fully characterized spectroscopically (1H and 13C NMR, IR, MS) and the data is in

Electrochemical cyclization of alkynes to construct five-membered nitrogen-heterocyclic rings

• Lifen Peng,
• Ting Wang,
• Zhiwen Yuan,
• Bin Li,
• Zilong Tang,
• Xirong Liu,
• Hui Li,
• Guofang Jiang,
• Chunling Zeng,
• Henry N. C. Wong and
• Xiao-Shui Peng

Beilstein J. Org. Chem. 2025, 21, 2173–2201, doi:10.3762/bjoc.21.166

• to excellent yields. When KI was used instead of NH4X, naphtho[1′,2′:4,5]furo[3,2-b]indoles 8 were generated in 43–72% yields. Performing the electrochemical bicyclization of 6' with NH4I in acetone yielded naphtho[1′,2′:5,6][1,3]oxazino[3,4-a]indoles 9 in moderate yields. It was worth mentioning

C2 to C6 biobased carbonyl platforms for fine chemistry

• Jingjing Jiang,
• Muhammad Noman Haider Tariq,
• Florence Popowycz,
• Yanlong Gu and
• Yves Queneau

Beilstein J. Org. Chem. 2025, 21, 2103–2172, doi:10.3762/bjoc.21.165

• acid (ALA), and benzylic acid (BA). These acids were oxidized and gave formaldehyde, acetaldehyde, acetone, benzaldehyde, acetophenone, and benzophenone, respectively. By increasing pH and concentration, the rate of the reactions increased, but decreased upon increasing the amount of Cl− ions (Scheme

Further elaboration of the stereodivergent approach to chaetominine-type alkaloids: synthesis of the reported structures of aspera chaetominines A and B and revised structure of aspera chaetominine B

• Jin-Fang Lü,
• Jiang-Feng Wu,
• Jian-Liang Ye and
• Pei-Qiang Huang

Beilstein J. Org. Chem. 2025, 21, 2072–2081, doi:10.3762/bjoc.21.162

• our third-generation strategy featuring the employment of benzyl ʟ-valinate as the coupling component [63], tripeptide derivative 28 was synthesized in three steps. Exposure of 28 to DMDO in acetone followed by treating the resulting intermediates with Na2SO3 produced the proposed structure of aspera

Switchable pathways of multicomponent heterocyclizations of 5-amino-1,2,4-triazoles with salicylaldehydes and pyruvic acid

• Yana I. Sakhno,
• Oleksander V. Buravov,
• Kostyantyn Yu. Yurkov,
• Anastasia Yu. Andryushchenko,
• Svitlana V. Shishkina and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2025, 21, 2030–2035, doi:10.3762/bjoc.21.158

• substituted salicylaldehydes are particularly interesting because of the possibility of additional reactions and post-cyclizations involving the o-hydroxy group. It was demonstrated [10][11][12] that the multicomponent reaction of substituted 3-amino-1,2,4-triazoles, various salicylaldehydes, and acetone

Photochemical reduction of acylimidazolium salts

• Michael Jakob,
• Nick Bechler,
• Hassan Abdelwahab,
• Fabian Weber,
• Janos Wasternack,
• Leonardo Kleebauer,
• Jan P. Götze and
• Matthew N. Hopkinson

Beilstein J. Org. Chem. 2025, 21, 1973–1983, doi:10.3762/bjoc.21.153

• was also observed in PhCF3 (11% of 2, 24% of 3, Table 1, entry 13) and acetone (14% of 2, 24% of 3, Table 1, entry 14), however, relatively complex reaction mixtures were obtained in either THF (4% of 2, 7% of 3, Table 1, entry 15) or DMF (Table 1, entry 16). At this stage, we returned our attention

Photoswitches beyond azobenzene: a beginner’s guide

• Michela Marcon,
• Christoph Haag and
• Burkhard König

Beilstein J. Org. Chem. 2025, 21, 1808–1853, doi:10.3762/bjoc.21.143

• -position give hypsochromic shifts and shorten the thermal half-life by stabilising the transition state 73’ (Scheme 23, bottom) [63]. Synthesis The classic synthesis of indigo is achieved via Baeyer–Drewsen synthesis reacting 2-nitrobenzaldehyde (74) and acetone in basic medium (Scheme 24, top) [91]. Since

Synthesis of an aza[5]helicene-incorporated macrocyclic heteroarene via oxidation of an o-phenylene-pyrrole-thiophene icosamer

• Yusuke Matsuo,
• Aoi Nakagawa,
• Shu Seki and
• Takayuki Tanaka

Beilstein J. Org. Chem. 2025, 21, 1561–1567, doi:10.3762/bjoc.21.119

• , along with decamer 3 (30%). High-resolution atmospheric-pressure-chemical-ionization time-of-flight mass-spectrometry (HR-APCI-TOF-MS) showed a molecular ion peak for 4 at m/z = 1479.4320 (calcd for C100H66N6S4, m/z = 1479.4305). The 1H NMR spectrum of 4 in acetone-d6 exhibited two NH signals at 9.07

• and 8.98 ppm and five doublet signals due to the heterole β-protons in the range of 6.7–5.8 ppm, along with o-phenylene protons around 7 ppm. Single crystals suitable for X-ray diffraction analysis were obtained from a mixture of acetone/n-hexane and the solid-state structure was successfully

General method for the synthesis of enaminones via photocatalysis

• Paula Pérez-Ramos,
• Raquel G. Soengas and
• Humberto Rodríguez-Solla

Beilstein J. Org. Chem. 2025, 21, 1535–1543, doi:10.3762/bjoc.21.116

• by DME, DMSO or acetone diminished the product yields (Table 1, entries 7–9). The reactivity of acridinium PC1 was superior to that of other photocatalysts, including 4-CzlPN (PC2) and [Ir(dF(CF3)ppy)2(dtbbpy)]PF6 (PC3) (Table 1, entries 10 and 11). Attempts to increase the temperature of the process

Tautomerism and switching in 7-hydroxy-8-(azophenyl)quinoline and similar compounds

• Lidia Zaharieva,
• Vera Deneva,
• Fadhil S. Kamounah,
• Nikolay Vassilev,
• Ivan Angelov,
• Michael Pittelkow and
• Liudmil Antonov

Beilstein J. Org. Chem. 2025, 21, 1404–1421, doi:10.3762/bjoc.21.105

• =O group of the keto tautomers [51][56]). The effects of acetone, methanol and DMSO, as seen, are based only on the increased (comparing to toluene) dielectric constant of the solvent, stabilizing in different extent the more polar KE and KK. The further increase of the polarity of the environment by