Study of the interaction of 2H-furo[3,2-b]pyran-2-ones with nitrogen-containing nucleophiles

• Constantine V. Milyutin,
• Andrey N. Komogortsev and
• Boris V. Lichitsky

Beilstein J. Org. Chem. 2025, 21, 556–563, doi:10.3762/bjoc.21.44

• structure of used N-nucleophile various types of a heterocyclic system can be obtained. A large number of examples of reactions with substituted amines have been reported in the literature. Generally, this process includes opening of the furanone ring followed by cyclization to the pyrrolone moiety [6][7][8

• pyrrolones such interaction can lead to pyridazinone systems [10][11]. Despite on the plenty of reactions with nitrogen-containing nucleophiles there is only one example of recyclization using furanone with a carbonyl group at position 3 (Scheme 1a, previous work) [6]. However, no work on this type of

• that, the use of 3-fold excess of amine 2a led to the same results. Apparently, the stability of salt 3a is connected with high acidity of the starting furanone 1a and its recovery is only possible under the action of strong acids (HCl, H2SO4). Further, we investigated the chemical behavior of

Advances in radical peroxidation with hydroperoxides

• Oleg V. Bityukov,
• Pavel Yu. Serdyuchenko,
• Andrey S. Kirillov,
• Gennady I. Nikishin,
• Vera A. Vil’ and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2024, 20, 2959–3006, doi:10.3762/bjoc.20.249

• ) species react with TBHP, resulting in the formation of a peroxocomplex of TBHP with Co(III) (stage B). The oxidation of 4-hydroxy-2(5H)-furanone 21 by Co(III)OO-t-Bu complex generates the target product 22 (step C). A second reaction pathway is also possible, in which the tert-butoxy radical A abstracts

• the hydrogen atom from TBHP to form the tert-butylperoxy radical (stage D). Next, tert-butylperoxy radical adds to the enol double bond of 4-hydroxy-2(5H)-furanone 21 (step E). Further oxidation of the resulting C-centered radical I into cation II and the proton transfer results in the target product

• 22 (steps F, G). The third possible pathway involves the abstraction of a hydrogen atom from 4-hydroxy-2(5H)-furanone 21 by the tert-butoxy radical formed in step A to give the alkoxy radical III (step H). Intermolecular hydrogen atom transfer results in the C-centered radical IV (step I). Further

Base-promoted cascade recyclization of allomaltol derivatives containing an amide fragment into substituted 3-(1-hydroxyethylidene)tetronic acids

• Andrey N. Komogortsev,
• Constantine V. Milyutin and
• Boris V. Lichitsky

Beilstein J. Org. Chem. 2024, 20, 2585–2591, doi:10.3762/bjoc.20.217

• synthesized products is different from previously described 3-acetyltetronic acids 2 obtained from the corresponding hydrazides 1. As well as in the case of compounds 2 for the amide derivatives 4 the double bond between pyrrolidinone and furanone parts has E-configuration. Only for sterically hindered

• formation of an intramolecular hydrogen bond and the double bond is located in the furanone ring. In contrast to the aforementioned example the considered compounds 4 have an exocyclic enol fragment and the intramolecular hydrogen bond is connected to the carbonyl oxygen atom. Thus, the absence of

Entry to new spiroheterocycles via tandem Rh(II)-catalyzed O–H insertion/base-promoted cyclization involving diazoarylidene succinimides

• Alexander Yanovich,
• Anastasia Vepreva,
• Ksenia Malkova,
• Grigory Kantin and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2024, 20, 561–569, doi:10.3762/bjoc.20.48

• also in the alpha position of the furanone ring. Reactions with allenic acids 11 were carried out according to a similar scheme, in the one-pot mode, without isolation of OH-insertion intermediates 12 (Scheme 4). In order to accelerate the cyclization step in this case, moderate heating was used after

• of DIPEA (60 mol %), which can be explained by the presence of EDG in the corresponding DAS. In general, the second step of the process appears to occur as endo-cyclization onto an activated multiple bond followed by migration of the remaining endocyclic double bond into the furanone ring. The

Synthesis of sulfur karrikin bioisosteres as potential neuroprotectives

• Martin Pošta,
• Václav Zima,
• Lenka Poštová Slavětínská,
• Marika Matoušová and
• Petr Beier

Beilstein J. Org. Chem. 2022, 18, 549–554, doi:10.3762/bjoc.18.57

• concentrations [11][12][13][14]. Structurally, the karrikin backbone consists of a fused pyran and a furanone ring. Each particular molecule differs in the number of methyl groups in positions C3, C5 and C7. Structures of the four most active and abundant karrikins (KAR1–KAR4) are depicted in Figure 1. The

• synthesis of these heterocycles is rather challenging, because the fused pyran and furanone system cannot be easily prepared by standard cyclization methods [15][16][17]. Although karrikins are extremely active plant growth regulators [14][18][19], their biological activity in humans was not investigated

Menadione: a platform and a target to valuable compounds synthesis

• Acácio S. de Souza,
• Ruan Carlos B. Ribeiro,
• Dora C. S. Costa,
• Fernanda P. Pauli,
• David R. Pinho,
• Matheus G. de Moraes,
• Fernando de C. da Silva,
• Luana da S. M. Forezi and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 381–419, doi:10.3762/bjoc.18.43

• ) triflate-catalyzed reaction showed the best results in terms of performance, producing furanone 56 in 65% yield. Additionally, this study was also extended to the synthesis of hetero-tetracyclic derivatives containing endocyclic nitrogen atoms. The best result was obtained using triene 57, and 2.0

Dawn of a new era in industrial photochemistry: the scale-up of micro- and mesostructured photoreactors

• Emine Kayahan,
• Mathias Jacobs,
• Leen Braeken,
• Leen C.J. Thomassen,
• Simon Kuhn,
• Tom van Gerven and
• M. Enis Leblebici

Beilstein J. Org. Chem. 2020, 16, 2484–2504, doi:10.3762/bjoc.16.202

• with a length of 11.5 m and an inner diameter of 0.8 mm were wrapped around two Pyrex® glass columns. UV lamps were placed inside the glass columns. A representative setup is given in Figure 3a. The addition of isopropanol to 2(5H)-furanone in the presence of the photosensitizer 4,4’-dimethoxy

Ultrasonic-assisted unusual four-component synthesis of 7-azolylamino-4,5,6,7-tetrahydroazolo[1,5-a]pyrimidines

• Yana I. Sakhno,
• Maryna V. Murlykina,
• Oleksandr I. Zbruyev,
• Anton V. Kozyryev,
• Svetlana V. Shishkina,
• Dmytro Sysoiev,
• Vladimir I. Musatov,
• Sergey M. Desenko and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2020, 16, 281–289, doi:10.3762/bjoc.16.27

• enabled us to develop highly selective procedures for obtaining triazolo-, tetrazolo-, and pyrazolopyrimidines [4][5][16][17][18][19][20][27][28][29], as well as oxygen-bridged tetrahydropyrazolopyrimidines [4][19], furanone [17][30], and pyrrolone derivatives [5][16][17][18]. Besides the presence of an

Natural products from microbes associated with insects

• Christine Beemelmanns,
• Huijuan Guo,
• Maja Rischer and
• Michael Poulsen

Beilstein J. Org. Chem. 2016, 12, 314–327, doi:10.3762/bjoc.12.34

• )), sesquiterpenes with an unprecedented carbon skeleton that are most likely built up by an enzymatic Aldol addition. In a similar example, new cytotoxic furanone analogues (e.g., paraconfuranone A (39)) were obtained from the fungus Paraconiothyrium brasiliense isolated from the gut of the grasshopper Acrida

Recent applications of ring-rearrangement metathesis in organic synthesis

• Sambasivarao Kotha,
• Milind Meshram,
• Priti Khedkar,
• Shaibal Banerjee and
• Deepak Deodhar

Beilstein J. Org. Chem. 2015, 11, 1833–1864, doi:10.3762/bjoc.11.199

• the fruiting body of P. igniarius, is a well-known anticancer agent. To assemble the spiro-fused furanone core of phelligridin G, Wright and Cooper [55] have used a RRM process as a key step. Wittig olefination of furylbenzaldehyde derivative 265 using methyltriphenylphosphonium bromide in the

• pyran derivatives. RRM of various functionalized oxanorbornene systems. RRM to assemble the spiro fused-furanone core unit. (i) 129, benzene, 55 °C, 3 days; (ii) Ph3P=CH2Br, n-BuLi, THF, 0 °C; (iii) 129, benzene, 40 °C, 24 h; (iv) catalyst 2 (10 mol %), CH2Cl2, 35 °C. RRM protocol to norbornenyl sultam

Preparative semiconductor photoredox catalysis: An emerging theme in organic synthesis

• David W. Manley and
• John C. Walton

Beilstein J. Org. Chem. 2015, 11, 1570–1582, doi:10.3762/bjoc.11.173

• probably involved the coupling of the initial aminium radical cation with the radical anion formed by SET to the furanone substrate [46]. An interesting further convolution was observed in the TiO2 and ZnS promoted SCPC reactions of N,N-dimethylaniline (10) with furanone 6. A tandem radical addition

Application of cyclic phosphonamide reagents in the total synthesis of natural products and biologically active molecules

• Thilo Focken and
• Stephen Hanessian

Beilstein J. Org. Chem. 2014, 10, 1848–1877, doi:10.3762/bjoc.10.195

• through a conjugate addition sequence employing phosphonamide 28c, thereby setting two of the three stereocenters of the five-membered ring in a single step. Thus, deprotonation of chiral phosphonamide 28c and addition of the anion to 2(5H)-furanone (176) at −100 ºC, followed by trapping with excess

A tandem Mannich addition–palladium catalyzed ring-closing route toward 4-substituted-3(2H)-furanones

• Jubi John,
• Eliza Târcoveanu,
• Peter G. Jones and
• Henning Hopf

Beilstein J. Org. Chem. 2014, 10, 1462–1470, doi:10.3762/bjoc.10.150

• . Keywords: aza-prostaglandin analogue; 3(2H)-furanone; Mannich addition; palladium catalysis; tandem reaction; Introduction Organic chemists welcome the introduction of facile tandem protocols because of the advantages of multiple bond formation in one-pot processes, which in turn makes the process

• closure of the primary adduct to form the furanone. In this paper, we report our investigations that extend the reaction to heteroatom-containing electrophiles such as imines and diazo esters. Results and Discussion Following the work on nitrostyrenes, Yan et al. also reported a two-step asymmetric route

• commenced our investigations with the reaction of tosylimine 1a and ethyl 4-chloroacetoacetate (2a) in the presence of 5 mol % of Pd(PPh3)4 and 2.0 equivalents of Na2CO3, in dioxane at 50 °C for 10 hours. The reaction afforded 4-substituted-3(2H)-furanone 3 in 57% yield (Scheme 2). Interestingly, we could

Recent applications of the divinylcyclopropane–cycloheptadiene rearrangement in organic synthesis

• Sebastian Krüger and
• Tanja Gaich

Beilstein J. Org. Chem. 2014, 10, 163–193, doi:10.3762/bjoc.10.14

• acid was converted to the corresponding anhydride, which could be reduced to the alcohol using NaBH4, followed by reoxidation with DMP to yield aldehyde 154. Attachment of furanone enolate 155 [134][135], followed by reoxidation yielded tricycle 156. Deprotection of the amine and the MOM-protected

Stereodivergent synthesis of jaspine B and its isomers using a carbohydrate-derived alkoxyallene as C₃-building block

• Volker M. Schmiedel,
• Stefano Stefani and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2013, 9, 2564–2569, doi:10.3762/bjoc.9.291

• -azido group overcoming the steric hindrance of the slim alkyl chain. We assume that in both diastereomers the azido group occupies a pseudoaxial position shielding this face of the furanone ring and therefore steers the hydride attack to the other side. Similar observations have been reported for the

Microflow photochemistry: UVC-induced [2 + 2]-photoadditions to furanone in a microcapillary reactor

• Sylvestre Bachollet,
• Kimitada Terao,
• Shin Aida,
• Yasuhiro Nishiyama,
• Kiyomi Kakiuchi and
• Michael Oelgemöller

Beilstein J. Org. Chem. 2013, 9, 2015–2021, doi:10.3762/bjoc.9.237

• , Takayama-cho, Ikoma, Nara 630-0101, Japan 10.3762/bjoc.9.237 Abstract [2 + 2]-Cycloadditions of cyclopentene and 2,3-dimethylbut-2-ene to furanone were investigated under continuous-flow conditions. Irradiations were conducted in a FEP-microcapillary module which was placed in a Rayonet chamber

• chemistry; furanone; microflow chemistry; photochemistry; Introduction Continuous-flow chemistry has recently emerged as a new methodology in organic chemistry [1][2][3][4]. The combination of microstructured dimensions and flow operations has also proven advantageous for photochemical applications [5][6

• concentrated to dryness and the crude product was analyzed by 1H NMR spectroscopy. Conversions were determined by comparing the integration areas of selected signals from the starting furanone and the cycloaddition product. In selected cases, the pure products were isolated by column chromatography for

Flow photochemistry: Old light through new windows

• Jonathan P. Knowles,
• Luke D. Elliott and
• Kevin I. Booker-Milburn

Beilstein J. Org. Chem. 2012, 8, 2025–2052, doi:10.3762/bjoc.8.229

When cyclopropenes meet gold catalysts

• Frédéric Miege,
• Christophe Meyer and
• Janine Cossy

Beilstein J. Org. Chem. 2011, 7, 717–734, doi:10.3762/bjoc.7.82

• products: Furanone 35a (52%) and indene 36a (20%). The former compound arose from intramolecular trapping of the intermediate organogold species 37a by the carbonyl group of the ester at C3, followed by hydrolysis of the resulting α-methoxyfuran 38a. A similar result was reported by Wang et al. [21

• two compounds: Furanone 35a (40%) and indene 36a (39%) both devoid of a trimethylsilyl group. Since protodesilylation took place readily, it is likely that the allylic silanes 35’e and 36’e were the initially generated products. Their formation could be explained by regioselective electrophilic