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

• ketophosphonate 169 using MePO(OMe)2 and n-BuLi. Notably, building block 171 used herein can be synthesized from 170 within 6 steps including a kinetic resolution with Amano lipase PS-800. [94] Another fragment, 181, was synthesized from alcohols 173 and 174, which were perpared from tri-O-acetyl-ᴅ-glucal and (S

• . Reductive N–O bond cleavage and stereospecific reduction with Me4NBH(OAc)3 yielded diol 198, whose primary alcohol unit was PMB-protected, while the secondary one was methylated. Dihydroxylation and protection with 2,2-dimethoxypropane yielded 199. Then, desilylation with TBAF and DMP-oxidation led to

• ; (m) TBDMSCl, imidazole, DCM, 50 °C; (n) DIBAL-H, toluene, −78 °C; (o) 36, n-BuLi, −78 to −50 °C; (p) i. DMP, DCM, rt; ii. SmI2, MeOH, THF, −78 to −50 °C; 18-crown-6: 1,4,7,10,13,16-hexaoxacyclooctadecane, 9-BBN: 9-borabicyclo[3.3.1]nonane, (±)-CSA: camphorsulfonic acid. Synthesis of 79. Above

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

• by the disappearance of the characteristic signals of the ethyl group and an upfield shift of 0.27 ppm for the O–CH2 protons compared to the spectrum of the PCP ester. However, signals corresponding to DBU at 1.5, 2.3, and 3.1 ppm were still observed (Supporting Information File 1, Figure S7) despite

• %). The structure of PCP HA was fully characterized by 1H NMR and 13C NMR (DMSO-d6) as well as by HRMS (ESI+) (Figures S3–S6, and S9 in Supporting Information File 1). In the 1H NMR spectrum, two sets of singlets at 4.41 and 4.76 ppm (CH2) were attributed to the –O=C–CH2–O– groups of the E/Z isomers of

Recent advances in the stereoselective synthesis of distal biaxially chiral molecules

• Fanxing Zhou,
• Chen Zhang,
• Lingyu Sun,
• Yiyun Fang,
• Siming Zheng,
• Lina Hu,
• Mengyang Shen,
• Zhen Zhao,
• Wei Xu,
• Yunqiang Sun and
• Zi-Qiang Rong

Beilstein J. Org. Chem. 2026, 22, 461–479, doi:10.3762/bjoc.22.34

• [2 + 2 + 2] cycloaddition reaction between α,ω-diynes 1 and monoalkynes 2, providing an alternative to traditional asymmetric coupling strategies for the synthesis of C2-symmetric biaryl chiral compounds (Scheme 1a) [40]. They further demonstrated the feasibility of constructing N-, O-, and C

Synthesis and stereochemical analysis of dynamic planar chiral oxa[7]orthocyclophene

• Yukiho Hashimoto,
• Yuuya Kawasaki,
• Kazunobu Igawa and
• Katsuhiko Tomooka

Beilstein J. Org. Chem. 2026, 22, 436–442, doi:10.3762/bjoc.22.30

• ][3][4][5][6][7][8][9][10], we previously synthesized hetera[7]orthocyclophenes 1 having a heteroatom-embedded ansa-chain (X = O or NR) and an (E)-alkene moiety (Figure 1) [6][9], and found that the orthocyclophenes exhibit dynamic planar chirality in a wide range of stereochemical stability depending

• on the differences of the heteroatom and substituents on the (E)-alkene moiety [11][12]. The half-lives of the optical activity optt1/2 of 1aa (X = O, Y = H) and 1ba (X = NTs, Y = H) were 380 h and 56.7 h at 25 °C, respectively, indicating that the stereochemical stability of the oxygen-containing

• -substituted oxacyclophenes 1ab (X = O, Y = Me), 1ac (X = O, Y = Ph), and 1ad (X = O, Y = I), in which 1ad was used as the key intermediate for the synthesis of 1ab and 1ac via Kumada–Tamao coupling with Grignard reagents (Figure 2). Results and Discussion Retrosynthesis and synthesis of the C6-iodo

Synthesis and anti-cancer activity of naphthalimide–organylselanyl conjugates

• Rajkumar Ravi and
• Selvakumar Karuthapandi

Beilstein J. Org. Chem. 2026, 22, 416–435, doi:10.3762/bjoc.22.29

• ···C distance of 3.588 Å. Third and fourth, as shown in Supporting Information File 1, Figure S20, the intermolecular interaction of C–H···O, having an H···O distance of 2.544 Å and the (π···π) interaction having a C···C distance of 3.376 Å, stabilise and glue the self-assembled architecture in the

• selenium center. The second important feature is the torsional motion in the propylene linker attached to the imide nitrogen of the naphthalimide core. The calculated O–C–C–C torsional angle from the gas-phase structure of 7 is −61.5°. The observed torsional angle from the solid-state structure of 7 is

• −69.7°. This shows good agreement between the solid-state and gas-phase geometries of 7. In contrast, although a solid-state structure is not available, the computed O–C–C–C torsional angle from the gas-phase geometry of 8 is 179.7°. The comparison of the computed torsional angles between the two

Cone p-aminocalix[4]arenes enriched with ‘clickable’ alkyne or azide functionalities

• Ilia Korniltsev,
• Vasily Bazhenov,
• Alexander Gorbunov,
• Dmitry Cheshkov,
• Stanislav Bezzubov,
• Vladimir Kovalev and
• Ivan Vatsouro

Beilstein J. Org. Chem. 2026, 22, 399–415, doi:10.3762/bjoc.22.28

• conformational interconversions), thereby favoring or disfavoring the C4v-symmetric ‘ideal’ cone conformation of the calixarene core required for capsule formation [59]. To check this, 1H NMR spectra from the CDCl3 solutions of multifunctionalized calixarenes 47–51 and their 1:1 mixtures with the known O

Design, synthesis and biological evaluation of 2,5-diaryloxazolo[4,5-d]pyrimidin-7-ylamines as selective cytotoxic agents against HeLa cells

• Maryna V. Kachaeva,
• Agnieszka B. Olejniczak,
• Marta Denel-Bobrowska,
• Victor V. Zhirnov,
• Yevheniia S. Velihina,
• Stepan G. Pilyo and
• Volodymyr S. Brovarets

Beilstein J. Org. Chem. 2026, 22, 390–398, doi:10.3762/bjoc.22.27

• spectroscopy, LC–MS and elemental analysis (Supporting Information File 1, Figures S1–S36). The IR spectra of compounds 1–5 showed the presence of NH absorption bands in the range 3381–2936 cm−1, OH at 3396 cm−1 (compound 9), and C=O at 1601–1610 cm−1 (compounds 6-8). Cytotoxic potency of the compounds 1–9

• CDCl3 or CF3C(O)OD, taking its residual solvent signal as a standard. Multiplicities were described using the following abbreviations: s = singlet, br s = broad singlet, d = doublet, dd = doublet of doublets, t = triplet, and m = multiplet. LC–MS analysis was performed on an Agilent 1200 Series system

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

• of the quaternary ammonium salt in the presence of a O-, S- or N-nucleophile with cesium carbonate leads to a retro-Claisen reaction, ring-opening and Michael addition. The resulting novel 4-Nu-3-sulfonylbutan-1-amines are isolated in moderate to excellent overall yields. The reduction of the

• of the pyrrolidines 2. In this way, the hydride anion was formally added to the list of possible nucleophiles (H-, N-, O-, S-). Conclusion In conclusion, we developed a practical route to the novel skeleton of N,N-dialkyl-3-(sulfonyl)butan-1-amines from β-ketosulfones. The proposed approach exploits

Non-central chirality in organic chemistry

• Ken Tanaka and
• Naohiko Yoshikai

Beilstein J. Org. Chem. 2026, 22, 370–371, doi:10.3762/bjoc.22.24

• Ken Tanaka Naohiko Yoshikai Department of Chemical Science and Engineering, Institute of Science Tokyo, O-okayama, Meguro-ku, Tokyo 152-8550, Japan Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba-ku, Sendai 980-8578, Japan 10.3762/bjoc.22.24 Keywords: asymmetric synthesis

Recent advances in the cleavage of non-activated amides

• Eun-Sol Choi and
• Hyo-Jun Lee

Beilstein J. Org. Chem. 2026, 22, 352–369, doi:10.3762/bjoc.22.23

• electrophilic benzylating reagent (Scheme 7) [55]. DPT-BM functions as an O-benzylating reagent that generates benzyl cation equivalents upon dissolution in the solvent under non-acidic conditions. Thus, the reaction of an amide with DPT-BM is proposed to form a benzyl imidate salt J, which subsequently

• 1), addition of water affords adduct M, which subsequently converts to the ester via deprotonation. In dry solvents (path 2), nucleophilic attack by the departing OSO₂F− anion on L produces intermediate N, containing an S–O bond that is ultimately cleaved under basic conditions to yield the ester

• electrophilic activation of pyrrolidine-derived amides with Tf2O and 2-bromopyridine generates a keteniminium ion O, which undergoes nucleophilic addition to form an enamine intermediate P. Subsequent electrophilic α-fluorination followed by hydrolysis produces the α-fluoroester products. Notably, the C2-chiral

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

• carbocation 49b, which is quenched by a 1,4-alkyl shift of the aromatic system, and establishment of a C–O double bond at C-12 to give sespenine (50) as the product. In meroterpenoid biosynthesis, the transformation of andilesin C (51) towards the anditomin skeleton, as investigated by Abe and co-workers, is

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

• (Figure 2). Both compounds crystallize as racemates, Figure 3 displaying their unit cell fragments. In 4b, the two enantiomers are connected through weak hydrogen bonds (N–H···O 2.612 Å) between the barbiturate rings. In contrast, compound 4c exhibits classical hydrogen bonding (N–H···O 1.878 Å) linking

• contacts: the barbiturate ring forms hydrogen bonds with water molecules through C=O···H–O and N–H···O–H interactions; the amide group of the barbiturate ring is engaged in a C=O···H–N hydrogen bond with the carbonyl oxygen of the maleimide fragment; additionally, a C=O···H–CH2 contact is observed between

• the hydrogen atom of the maleimide methyl group and the carbonyl oxygen of an adjacent maleimide ring. The crystal structure of compound 4b exists as a solvate. The oxygen atom of a water molecule forms a hydrogen bond with the amide hydrogen of the barbiturate fragment (N–H···O–H = 2.783 Å), while

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

• unfolds in η2-naphthalene complexes, where transient formation of the less favored 2,3-η2-isomer imparts o-quinodimethane character (Figure 7) [52]. The third reactivity mode is purely activating in nature, with the metal acting as a π-donor that increases and localizes the electron density of the

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

• , were considered promising candidates due to the presence of two electron-withdrawing groups and their well-known facile decarboxylation properties. Literature reports indicated that Meldrum’s acid can introduce into molecule fragments containing the CH2C(O)R moiety, where R depends on the nucleophile

Conformational analysis of difluoromethylornithine: factors influencing its gas-phase and bioactive conformations

• Matheus P. Freitas

Beilstein J. Org. Chem. 2026, 22, 237–243, doi:10.3762/bjoc.22.17

• interactions (typically σCH → σ*CF) that stabilize conformations in which the C–F bonds adopt a gauche orientation relative to polar bonds, such as C–N or C–O [8][9][10]. In DFMO, the difluoromethyl group is directly connected to the ornithine backbone, and its conformation is expected to be shaped not only by

• part because its C–N bond is not flanked by two C–F bonds. At the other extreme, structure 13 is highly destabilized sterically due to folding of the N-alkyl chain, which brings N–H and C–N bonds into close contact with C–H, C–C, and C=O bonds. This geometry generates several n/σ and σ/σ interactions

• )/CBS level of theory. Color labels: H = white, C = grey, N = blue, O = red, F = electric blue. (S)-DFMO bound within the active site of human arginase I obtained from the Protein Data Bank (3GN0) (https://doi.org/10.2210/pdb3gn0/pdb, [21]). Dotted lines represent hydrogen-bonding interactions with

Base-promoted deacylation of 2-acetyl-2,5-dihydrothiophenes and their oxygen-mediated hydroxylation

• Vladimir G. Ilkin,
• Margarita Likhacheva,
• Igor V. Trushkov,
• Tetyana V. Beryozkina,
• Vera S. Berseneva,
• Vladimir T. Abaev,
• Wim Dehaen and
• Vasiliy A. Bakulev

Beilstein J. Org. Chem. 2026, 22, 192–204, doi:10.3762/bjoc.22.13

• ], oxygen [23][24] or with m-CPBA (Scheme 1B) [25][26] or non-catalytic transformations [27]. The few known oxidative transformations of o- or p-hydroxy-substituted aromatic ketones, that in most cases lead to phenols, involve the use of hydrogen peroxide as an oxygen source (Scheme 1C) [20][25][26

• phenols [25]. Hocking has described the oxidation of o-hydroxyacetophenone and some benzophenones with an aqueous alkaline hydrogen peroxide solution [26]. The key steps of oxidation of ketones into phenols include: a) nucleophilic addition of the hydroperoxide anion to the carbonyl carbon; b) [1,2]-aryl

• due to the stronger donor character of the pyrrolidine moiety due to its planar structure. The formation of the deacetylated products 2n,o (Scheme 2) may be attributed to increased steric hindrance, which makes proton transfer to B in Scheme 6 more difficult. The dimethyl-1-yl moiety likely exhibits a

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

• '. HMBC correlations were observed from the sp3 methylene proton H2-11 to C-8, C-1', and the oxygenated sp2 quaternary carbon C-6' (δ 143.8). These correlations indicated that the quinoline unit was fused to a drimane-type sesquiterpene through two key links: a C–O bond between C-8 and C-6' and a C–C bond

Improved synthesis and physicochemical characterization of the selective serotonin 2A receptor agonist 25CN-NBOH

• Adrian G. Rossebø,
• Hannah G. Kolberg,
• Anders E. Tønder,
• Louise Kjaerulff,
• Poul Erik Hansen,
• Karla A. Frydenvang,
• Jesper Østergaard and
• Jesper L. Kristensen

Beilstein J. Org. Chem. 2026, 22, 175–184, doi:10.3762/bjoc.22.11

• be partially responsible for its high membrane permeability. To investigate if an IMHB is indeed present in 1, we combined DFT calculations with NMR spectroscopy titrations. For a system containing an IMHB, it would be expected that replacing the proton (O–H) with a deuteron (O–D) would lead to an

• was obtained for the structure with two water molecules hydrogen-bonded to the OH and NH groups. The predicted isotope effect was calculated as the difference between the computationally predicted 13C chemical shift for the regular model and for models where each O–H and N–H bond was shortened by 0.01

Circumventing Mukaiyama oxidation: selective S–O bond formation via sulfenamide–alcohol coupling

• Guoling Huang,
• Huarui Zhu,
• Shuting Zhou,
• Wanlin Zheng,
• Fangpeng Liang,
• Zhibo Zhao,
• Yifei Chen and
• Xunbo Lu

Beilstein J. Org. Chem. 2026, 22, 158–166, doi:10.3762/bjoc.22.9

• interest due to their unique reactivity and value as intermediates in molecular design and medicinal chemistry [5][6][7][8][9][10] (Figure 1). In contrast, sulfinimidate esters, which feature a tetravalent sulfur–oxygen (S(=N)–O) motif, remain a relatively underexplored subclass of organosulfur compounds

• [11][12][13][14]. The highly polarized S–O bond imparts distinctive reactivity, making them promising modular electrophilic intermediates for the construction of complex and functionally rich sulfur–nitrogen architectures [14]. Despite their synthetic potential, general and efficient methods for the

• conditions, the selective S–O bond formation has been largely overlooked, rendering the direct synthesis of sulfinimidate esters from alcohols a nontrivial and underdeveloped transformation. Results and Discussion To validate our hypothesis and identify optimal conditions for sulfilimidate ester formation

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

• (electron) pair – the π-system of the nitro group, and bonds of the Cl···O, Cl···N, C–H···X (X = Cl, O, N) are realized, which are shown in Figures S47–S57 in Supporting Information File 1. The energy of such interactions can be comparable with the energy of “classical” hydrogen bonds [47]. Conclusion In

Advances in Zr-mediated radical transformations and applications to total synthesis

• Hiroshige Ogawa and
• Hugh Nakamura

Beilstein J. Org. Chem. 2026, 22, 71–87, doi:10.3762/bjoc.22.3

• bond dissociation energy (BDE). Although zirconium shares many characteristics with titanium as a group-congener transition metal, it is known to form stronger bonds in several cases. For example, the Ti–O BDE is reported as 115 kcal·mol−1, whereas the Zr–O BDE is 132 kcal·mol−1 [4]; likewise, Ti–Br

• molecules such as allose (23i) and cholesterol (23k), delivering the desired alcohols in good yields with excellent regioselectivity. The proposed mechanism is shown in Scheme 5C. Homolytic cleavage of the C–O bond in the epoxide generates a strong Zr–O bond, while the resulting alkyl radical abstracts a

• , affording the corresponding alcohol 28. In contrast, when substrates bearing a benzylic alcohol moiety at the α-position were subjected to the same conditions, the reaction proceeded through radical intermediate 31, which underwent a 1,5-hydrogen atom transfer (1,5-HAT) followed by intramolecular C–O bond

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

• %) and putative 6 (10%) formed (Table 1, entry 5). Both 7 and putative 6 likely arise from dianion interconversions, potentially mediated by LDA, that proceed at rates comparable to the subsequent methylation events. Of note, no O-alkylation side products were observed, which we attribute to the lower

• nucleophilicity of the intermediate lithium alkoxides and to the softer nucleophilic character at C vs O for lithium dienolates. While the dianion strategy was able to convert maltol (2) to ethylmaltol (1) in yields of up to 57%, the reactions suffered from an unsatisfactory purity profile. First, interconversion

• substrate for methylation, affording O-methyl ethylmaltol (9c) in moderate yield (45%, Table 2, entry 3). Subsequent O-demethylation of 9c to ethylmaltol (1) was achieved with boron tribromide in dichloromethane in 65% yield. While an O-methyl group proved successful, the unsatisfactory overall efficiency

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

• 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 Vladimir A. Tartakovsky N.D. Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences, 47 Leninsky prosp., 119991 Moscow

• phytopathogenic fungi. Keywords: ammonium dinitramide; antifungal agents; azoxy compounds; electrosynthesis; NO donors; Introduction Organic compounds containing N–N and N–O bonds are ubiquitous in diverse fields, including pharmaceuticals, agrochemicals, natural products [1][2][3][4], as well as in

• , structures, and redox properties, effective synthetic strategies for the construction of N–N and N–O systems remain markedly underdeveloped. Unlike traditional methods for constructing C–C and C–Het bonds, the number of methods for selective N–N [1][5][19][20][21][22][23][24][25][26][27][28][29] and N–O [30

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

• Svetlana O. Kushch Marina V. Goryaeva Yanina V. Burgart Marina A. Ezhikova Mikhail I. Kodess Pavel A. Slepukhin Alexandrina S. Volobueva Vladimir V. Zarubaev Victor I. Saloutin Postovsky Institute of Organic Synthesis of the Ural Branch of the Russian Academy of Sciences, S. Kovalevskoy St. 22/20

• , 620066 Ekaterinburg, Russian Federation Saint-Petersburg Pasteur Institute, Mira St. 14, 197101 Saint-Petersburg, Russian Federation 10.3762/bjoc.21.209 Abstract The use of 1,3-diamino-2-propanol with competitive N- and O-nucleophilic centers in a three-component cyclization with ethyl 4,4,4

• trifluoroacetoacetate (1) with methyl ketones 2. This reagent has alternative N- and O-reactive centers and thus can react as an N,N- or N,O-dinucleophile, generating in a single synthesis trifluoromethyl octahydropyrido[1,2-a]pyrimidin-6-ones or hexahydrooxazolo[3,2-a]pyridin-5-ones, or both that contain an additional

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

• Gabor Berecz Andras Dancso Maria Tothne Lauritz Lorand Kiss Gyula Simig Balazs Volk Egis Pharmaceuticals Plc., Directorate of Drug Substance Development, P. O. Box 100, H-1475 Budapest, Hungary HUN-REN Research Centre for Natural Sciences, Institute of Organic Chemistry, Stereochemistry Research