Synthesis of the aggregation pheromone of Tribolium castaneum

• Biyu An,
• Xueyang Wang,
• Ao Jiao,
• Qinghua Bian and
• Jiangchun Zhong

Beilstein J. Org. Chem. 2025, 21, 510–514, doi:10.3762/bjoc.21.38

• male, is attractive to both sexes [12]. Later, Suzuki identified the compound as 4,8-dimethyldecanal [13]. Mori synthesized four possible stereoisomers of 4,8-dimethyldecanal, and found that the response of T. castaneum to the (4R,8R)-isomer was identical to the natural pheromone [14][15]. In 2011

• , Mori and Phillips achieved the complete separation of the derivatives from the four stereoisomers by reversed-phase HPLC at −54 °C, and revealed that the natural pheromone consists of four stereoisomers of 4,8-dimethyldecanal (Figure 1) [16][17]. Previous syntheses mainly focused on chiral sources of

New tandem Ugi/intramolecular Diels–Alder reaction based on vinylfuran and 1,3-butadienylfuran derivatives

• Yuriy I. Horak,
• Roman Z. Lytvyn,
• Andrii R. Vakhula,
• Yuriy V. Homza,
• Nazariy T. Pokhodylo and
• Mykola D. Obushak

Beilstein J. Org. Chem. 2025, 21, 444–450, doi:10.3762/bjoc.21.31

• agree with our previous results on tandem acylation/Diels–Alder reactions [31][32][33] and lead us to conclude that the final Diels–Alder reaction products are formed as the exo-adducts. Moreover, since we do not observe other stereoisomers we speculate that the Ugi and Diels–Alder reactions occur under

Three-component reactions of conjugated dienes, CH acids and formaldehyde under diffusion mixing conditions

• Dmitry E. Shybanov,
• Maxim E. Kukushkin,
• Eugene V. Babaev,
• Nikolai V. Zyk and
• Elena K. Beloglazkina

Beilstein J. Org. Chem. 2025, 21, 262–269, doi:10.3762/bjoc.21.18

• cyanoacetic ester and acetylacetone. The configuration of the products 4 and 5 was established by bromination of a small amount of these isomeric compounds in CDCl3 (Scheme 6) and subsequent analysis of the mixture by 1H NMR spectroscopy. For the stereoisomers 4, the main product was lactone 22, identified by

Recent advances in electrochemical copper catalysis for modern organic synthesis

• Yemin Kim and
• Won Jun Jang

Beilstein J. Org. Chem. 2025, 21, 155–178, doi:10.3762/bjoc.21.9

• standard conditions. Subsequently, radical-polar coupling between electrophilic Ni-bound α-carbonyl radical intermediate 45 and remaining nucleophilic Cu-enolate 44 provides a chiral product 42 containing vicinal quaternary stereocenters with high stereoselectivity, and all three possible stereoisomers of

Synthesis of extended fluorinated tripeptides based on the tetrahydropyridazine scaffold

• Thierry Milcent,
• Pascal Retailleau,
• Benoit Crousse and
• Sandrine Ongeri

Beilstein J. Org. Chem. 2024, 20, 3174–3181, doi:10.3762/bjoc.20.262

• the two conformers of hydrazones 3e and 3f (see Supporting Information File 1) is in accordance with the E stereoisomers. Furthermore, another correlation is observed for one conformer involving the NH of the imine on one side and the α-proton and the CH2 of the Cbz of the phenylalanine on the other

Hypervalent iodine-mediated intramolecular alkene halocyclisation

• Charu Bansal,
• Oliver Ruggles,
• Albert C. Rowett and
• Alastair J. J. Lennox

Beilstein J. Org. Chem. 2024, 20, 3113–3133, doi:10.3762/bjoc.20.258

• of unsaturated alcohols and carboxylic acids to make tetrahydrofurans, fluoromethyl-γ-lactones and tetrahydropyrans. The ratio of stereoisomers is shown in parentheses. Oxyfluorination of unsaturated alcohols. Synthesis and mechanism of fluoro-benzoxazepines. Intramolecular fluorocyclisation of

HFIP as a versatile solvent in resorcin[n]arene synthesis

• Hormoz Khosravi,
• Valeria Stevens and
• Raúl Hernández Sánchez

Beilstein J. Org. Chem. 2024, 20, 2469–2475, doi:10.3762/bjoc.20.211

• from intermolecular dehydration, nowadays known as alkyl resorcin[4]arene. Forty years later in 1980, Höegberg noticed that short alkyl chain resorcin[n]arenes develop stereoisomers in the reaction mixture; however, since the condensation reaction is reversible, once the macrocycle adopts the bowl

Facile preparation of fluorine-containing 2,3-epoxypropanoates and their epoxy ring-opening reactions with various nucleophiles

• Yutaro Miyashita,
• Sae Someya,
• Tomoko Kawasaki-Takasuka,
• Tomohiro Agou and
• Takashi Yamazaki

Beilstein J. Org. Chem. 2024, 20, 2421–2433, doi:10.3762/bjoc.20.206

• in high to excellent yields without detection of any regio- as well as stereoisomers. The chirality contained in amines did not work efficiently for the stereochemical induction of the products (entries 6 and 7 in Table 2). In the case of secondary amines, the sterically demanding dibenzylamine

• of the stereoisomers when compared with the case of the compounds 3 [47][48]. Because control of the amount of PhCH2SH to 1.0 equiv did not give a positive effect, the conditions in entry 4 (Table 3) were eventually determined as the best. The different epoxyesters 2c–e were also applied for this

Natural resorcylic lactones derived from alternariol

• Joachim Podlech

Beilstein J. Org. Chem. 2024, 20, 2171–2207, doi:10.3762/bjoc.20.187

Understanding X-ray-induced isomerisation in photoswitchable surfactant assemblies

• Beatrice E. Jones,
• Camille Blayo,
• Jake L. Greenfield,
• Matthew J. Fuchter,
• Nathan Cowieson and
• Rachel C. Evans

Beilstein J. Org. Chem. 2024, 20, 2005–2015, doi:10.3762/bjoc.20.176

• to the AzoTAB, as seen in similar amphiphilic systems [30][31]. In the case of ionisation, both stereoisomers would be expected to be affected equally. In comparison to Azo, the AAP moiety is much more stable as the Z isomer, with a thermal half-life of 5.7 years at room temperature [13]. This means

1,2-Difluoroethylene (HFO-1132): synthesis and chemistry

• Liubov V. Sokolenko,
• Taras M. Sokolenko and
• Yurii L. Yagupolskii

Beilstein J. Org. Chem. 2024, 20, 1955–1966, doi:10.3762/bjoc.20.171

• Haszeldine et al. [49][100]. The reaction of individual E- or Z-isomer of 1,2-difluoroethylene and fluorinated ketones (Scheme 21) led to a mixture of stereoisomers in both cases, although for the E-isomer, about 70% of the product retained the starting configuration. Overall, (E)-1,2-difluoroethylene had

2-Heteroarylethylamines in medicinal chemistry: a review of 2-phenethylamine satellite chemical space

• Carlos Nieto,
• Alejandro Manchado,
• Ángel García-González,
• David Díez and
• Narciso M. Garrido

Beilstein J. Org. Chem. 2024, 20, 1880–1893, doi:10.3762/bjoc.20.163

• course of an extensive screening of NMDA (N-methyl-ᴅ-aspartate) channel blockers resembling 1,2-diphenylethylamines. A channel pharmacophore description was envisaged collecting data from stereoisomers of 1,2-diphenylethylamine derivatives and 1,2-dicyclohexylethylamine derivatives. Among them, isomer (S

Syntheses and medicinal chemistry of spiro heterocyclic steroids

• Laura L. Romero-Hernández,
• Ana Isabel Ahuja-Casarín,
• Penélope Merino-Montiel,
• Sara Montiel-Smith,
• José Luis Vega-Báez and
• Jesús Sandoval-Ramírez

Beilstein J. Org. Chem. 2024, 20, 1713–1745, doi:10.3762/bjoc.20.152

• compared to the stereoisomers 75, with enhanced activity observed upon substitution of the aromatic ring. Interestingly, hydrolysis of the acetate group on C-3 did not significantly affect the antiproliferative effect, indicating that the activity is primarily influenced by the stereochemistry and

Regio- and stereochemical stability induced by anomeric and gauche effects in difluorinated pyrrolidines

• Ana Flávia Candida Silva,
• Francisco A. Martins and
• Matheus P. Freitas

Beilstein J. Org. Chem. 2024, 20, 1572–1579, doi:10.3762/bjoc.20.140

• crystallographic data using the 3-fluoropyrrolidinium cation and 3-fluoropyrrolidine. Subsequently, we explored the relative energy of all favored conformations of all different stereoisomers of 2,3-, 2,4-, and 3,4-difluoropyrrolidines at the B3LYP-D3BJ/6-311++G** level. A generalized anomeric effect, arising from

• stereoisomers to influence preferred conformations when designing functional molecules. Experimental Computational details The benchmark study was conducted for 3-fluoropyrrolidine and 3-fluoropyrrolidinium cation to determine the optimal theoretical level for further investigations involving 2,3-, 2,4-, and

• (nN→σ*CF anomeric and σCH→σ*CF fluorine gauche effects) on the conformation of different stereoisomers is explored. MAE comparing the geometry parameters (bond length, bond angle, and dihedral angle) obtained from DFT calculations at the CCSD/DGTZVP level. The MAE for the crystal structure compared to

Stability trends in carbocation intermediates stemming from germacrene A and hedycaryol

• Naziha Tarannam,
• Prashant Kumar Gupta,
• Shani Zev and
• Dan Thomas Major

Beilstein J. Org. Chem. 2024, 20, 1189–1197, doi:10.3762/bjoc.20.101

• C6 position of the C6–C7 double bond leads to 4 distinct 6-6 bicyclic cationic stereoisomers (A–D, Figure 1). Reprotonation at the C3-position of the C2–C3 double bond forms 6-6 bicyclic compounds that are not observed in nature for eudesmanes as they proceed via a secondary carbocation [16

• moving in the order of increasing ring size (i.e., 5 to 6 to 7), we observe an increase in the standard deviation (variation in the difference in energy among the different stereoisomers). In case of the 6 membered (A–D), 7 membered (E–H) and 5 membered ring (I–L) cations, the standard deviations in

Enhancing structural diversity of terpenoids by multisubstrate terpene synthases

• Min Li and
• Hui Tao

Beilstein J. Org. Chem. 2024, 20, 959–972, doi:10.3762/bjoc.20.86

• substrates, MSTSs can also accept partially cyclized substrates. A class I diterpene synthase SiTPS8 from Setaria italicais is capable of utilizing three copalyl pyrophosphate (CPP) stereoisomers that were generated by different class II TSs, including ent-CPP (19), (+)-CPP (20), and syn-CPP (21), to

Three-component N-alkenylation of azoles with alkynes and iodine(III) electrophile: synthesis of multisubstituted N-vinylazoles

• Jun Kikuchi,
• Roi Nakajima and
• Naohiko Yoshikai

Beilstein J. Org. Chem. 2024, 20, 891–897, doi:10.3762/bjoc.20.79

• , producing the vicinal N-heterocycle-substituted olefin 9 as a mixture of stereoisomers in 65% yield. Finally, 4aa proved to be a viable nucleophilic VBX for the carboiodanation of 3-methoxybenzyne [35], furnishing the new ortho-alkenylated arylbenziodoxole 10 with exclusive C–C bond formation at the distal

Skeletal rearrangement of 6,8-dioxabicyclo[3.2.1]octan-4-ols promoted by thionyl chloride or Appel conditions

• Martyn Jevric,
• Julian Klepp,
• Johannes Puschnig,
• Oscar Lamb,
• Christopher J. Sumby and
• Ben W. Greatrex

Beilstein J. Org. Chem. 2024, 20, 823–829, doi:10.3762/bjoc.20.74

• , although 11a was sufficiently stable for filtration through a pad of silica. Applying these conditions and isolation protocols to all 3,3-disubstituted alcohols 10c–f gave moderate to excellent yields of the rearrangement products 11c–f as single stereoisomers. The reactions of alcohols 10b,d,e also gave

Genome mining of labdane-related diterpenoids: Discovery of the two-enzyme pathway leading to (−)-sandaracopimaradiene in the fungus Arthrinium sacchari

• Fumito Sato,
• Terutaka Sonohara,
• Shunta Fujiki,
• Akihiro Sugawara,
• Yohei Morishita,
• Taro Ozaki and
• Teigo Asai

Beilstein J. Org. Chem. 2024, 20, 714–720, doi:10.3762/bjoc.20.65

• stereoisomers, ent-CPP and syn-CPP. Class II TCs can also generate further structural diversity through hydride shifts, methyl shifts, and/or skeletal rearrangement of the labdadienyl+ diphosphate intermediate which is formed by the initial bicyclization. Following this class II TC-mediated cyclization, class I

Evaluation of the enantioselectivity of new chiral ligands based on imidazolidin-4-one derivatives

• Jan Bartáček,
• Karel Chlumský,
• Jan Mrkvička,
• Lucie Paloušová,
• Miloš Sedlák and
• Pavel Drabina

Beilstein J. Org. Chem. 2024, 20, 684–691, doi:10.3762/bjoc.20.62

• derivatives possess similar enantioselectivity. However, compound IV is less catalytically active, probably due to the lower acidity of protonated 1H-imidazole than 1H-tetrazole [17]. Conclusion In this study, we successfully synthesised enantiomerically pure stereoisomers of 2,2'-(pyridin-2,6-diyl)-bis

Enhanced reactivity of Li⁺@C₆₀ toward thermal [2 + 2] cycloaddition by encapsulated Li⁺ Lewis acid

• Hiroshi Ueno,
• Yu Yamazaki,
• Hiroshi Okada,
• Fuminori Misaizu,
• Ken Kokubo and
• Hidehiro Sakurai

Beilstein J. Org. Chem. 2024, 20, 653–660, doi:10.3762/bjoc.20.58

• signal at −12.4 (5a) and −13.5 ppm (5b), which clearly indicated that the Li+ was encapsulated in the highly shielded inner space of the fullerene cage. The observed chemical shift was almost identical to that of reported Li+@C60 derivatives [10][12][24]. Although the product 5a may have stereoisomers

(E,Z)-1,1,1,4,4,4-Hexafluorobut-2-enes: hydrofluoroolefins halogenation/dehydrohalogenation cascade to reach new fluorinated allene

• Nataliia V. Kirij,
• Andrey A. Filatov,
• Yurii L. Yagupolskii,
• Sheng Peng and
• Lee Sprague

Beilstein J. Org. Chem. 2024, 20, 452–459, doi:10.3762/bjoc.20.40

• of stereoisomers in 2:1 ratio. After isolation by distillation, 2,3-dibromo-1,1,1,4,4,4-hexafluorobutane (2) was characterized by 1H, 19F, 13C NMR and mass spectra. We studied the reaction of dibromoalkane 2 with various bases such as DBU, Hünig’s base (iPr2NEt), and potassium hydroxide (Table 1). In

• showed a mixture of stereoisomers with a 2:1 ratio. The dehydrohalogenation reaction of 2-chloro-3-iodo-1,1,1,4,4,4-hexafluorobutane (5) was studied. Like the dehydrobromination of alkane 2, the reaction of compound 5 with 1.3 equivalents of KOH in water in the presence of 5 mol % of Bu4NBr was carried

• , product 16 represented a mixture of stereoisomers in 2:1 ratio. After isolation by distillation butane 16 was characterized by 1H, 19F, 13C NMR and mass spectra. The reaction of alkane 16 with DBU in pentane as a solvent led exclusively to dehydrobromination with the formation of a mixture of (Z)- and (E

GlAIcomics: a deep neural network classifier for spectroscopy-augmented mass spectrometric glycans data

• Thomas Barillot,
• Baptiste Schindler,
• Baptiste Moge,
• Elisa Fadda,
• Franck Lépine and
• Isabelle Compagnon

Beilstein J. Org. Chem. 2023, 19, 1825–1831, doi:10.3762/bjoc.19.134

•  1b, featuring three stereoisomers of C8H15NO6). With the rapid development of our approach, such method now reached a high data output since a single IR fingerprint can be obtained in few seconds. The fast and automatic identification and classification of the data becomes compulsory, which motivates

• ion trap mass analyzer. The following monosaccharides were analyzed: three stereoisomers of hexosamine of chemical formula C6H13NO5, namely glucosamine (GlcN), galactosamine (GalN), mannosamine (ManN); and N-acetyl glucosamine (GlcNAc, chemical formula C8H15NO6). One typical spectrum of each of the

Unprecedented synthesis of a 14-membered hexaazamacrocycle

• Anastasia A. Fesenko and
• Anatoly D. Shutalev

Beilstein J. Org. Chem. 2023, 19, 1728–1740, doi:10.3762/bjoc.19.126

• that the geometry of the intermediate bis-amidrazone C facilitates macrocycle 5 formation. The DFT B3LYP/6-311++G(d,p) calculations of ten different tautomers and stereoisomers of bis-amidrazone C (DMSO and MeOH solutions) revealed that the structure shown in Scheme 6 is the most stable. Clearly, the

Synthesis of ether lipids: natural compounds and analogues

• Marco Antônio G. B. Gomes,
• Alicia Bauduin,
• Chloé Le Roux,
• Romain Fouinneteau,
• Wilfried Berthe,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2023, 19, 1299–1369, doi:10.3762/bjoc.19.96