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Search for "epoxidation" in Full Text gives 168 result(s) in Beilstein Journal of Organic Chemistry.
Recent advances in total synthesis of illisimonin A
Beilstein J. Org. Chem. 2025, 21, 2571–2583, doi:10.3762/bjoc.21.199
- then converted to vinyl iodide 26 via hydrazine formation followed by iodination using Barton’s method. Subsequent Bouvealt aldehyde synthesis and in situ reduction delivered allylic alcohol 27. Epoxidation of 27 with m-CPBA afforded the rearrangement precursor 28. Protonic acid-promoted semipinacol
- % yield (63% brsm) or 50% yield after four cycles with recovery of starting material. Selective epoxidation of the isopropenyl group with m-CPBA delivered cyclization precursor 45 as an inseparable mixture of diastereomers (dr = 1:2.1). A Cp2TiCl-mediated cyclization of 45 constructed the tricyclo
- [5.2.1.01,5]decane core with a cis-pentalene unit. The product was further processed into rearrangement precursor 46 (as an inseparable mixture, dr = 1:1.6) by TBS protection of the primary alcohol and epoxidation of the alkene with m-CPBA. Unlike Rychnovsky’s substrate, epoxy alcohol 46 underwent
Total syntheses of highly oxidative Ryania diterpenoids facilitated by innovations in synthetic strategies
Beilstein J. Org. Chem. 2025, 21, 2553–2570, doi:10.3762/bjoc.21.198
- , smoothly constructing the A ring to afford compound 14. Subsequent protection of the vicinal diol and aldehyde functionalities in 14 provides an intermediate that, after Baeyer–Villiger oxidation and subsequent tungsten-promoted reverse epoxidation, forms lactone 15. Ozonolysis of 15 cleaves the double
- compound 19. This intermediate is converted to lactone 20 via base-promoted Grob fragmentation followed by acid-mediated MOM deprotection. Epoxidation of the C10–C11 double bond in 20, lactone hydrolysis-promoted epoxide ring opening, and inversion of the C10 hydroxy configuration, yield the key
- intermediate 21, thereby completing the construction of the D ring. Adjustments of functional groups and oxidation states at multiple sites then afford anhydroryanodol (10). Finally, epoxidation of the C1–C2 double bond followed by Li/NH3-promoted reductive cyclization constructs the E ring of the molecular
Transformation of the cyclohexane ring to the cyclopentane fragment of biologically active compounds
Beilstein J. Org. Chem. 2025, 21, 2416–2446, doi:10.3762/bjoc.21.185
- the study of inflammatory diseases and other bioactive properties. Epoxidation of 230 with m-chloroperoxybenzoic acid (m-CPBA) gave the epoxide 231. Subsequent addition of excess BF3·OEt2 led to a semipinacol rearrangement, affording 232 in 65% yield as a single diastereomer. The aldehyde 232 was then
Recent advances in Norrish–Yang cyclization and dicarbonyl photoredox reactions for natural product synthesis
Beilstein J. Org. Chem. 2025, 21, 2315–2333, doi:10.3762/bjoc.21.177
- -chloroperoxybenzoic acid) induced epoxidation, which was then followed by a Meinwald rearrangement to accomplish aldehyde 7. From 7, a sequence involving silyl enol ether formation, Simmons−Smith cyclopropanation, and acid-mediated regioselective ring-opening installed the C8 quaternary methyl group in 10. Subsequent
- intramolecular aldehyde α-alkylation using MacMillan's protocol, subsequently undergoing Shi's asymmetric epoxidation to give rise to epoxide 60 as a 3:1 mixture of diastereomers. These were not separated until step 8 due to poor separability at this stage. Concurrently, diosgenin was then processed through a
- – was prepared from (+)-pulegone (77) through a six-step manipulation involving epoxidation, epoxide opening with sodium thiophenolate and subsequent concomitant retro-aldol, sulfoxidation, a one pot α-alkylation with acrylonitrile proceeding to thermal syn-elimination of phenylsulfenic acid, ketone
Halogenated butyrolactones from the biomass-derived synthon levoglucosenone
Beilstein J. Org. Chem. 2025, 21, 2297–2301, doi:10.3762/bjoc.21.175
- cascade to give enone 21 in 42% yield. Baeyer–Villiger oxidation of this highly activated alkene promoted an epoxidation/Baeyer–Villiger oxidation cascade to yield lactone 22 in 67% yield (dr 2:1). The low diastereoselectivity suggested that the epoxidation happened subsequent to the ring contraction, as
- the Baeyer–Villiger reaction without epoxidation may be challenging. Conclusion In conclusion, we have successfully established halogenation strategies of the biomass derivates 5 and 6, including fluorinations and trifluoromethylation. Baeyer–Villiger oxidations of these materials provide access to
Pathway economy in cyclization of 1,n-enynes
Beilstein J. Org. Chem. 2025, 21, 2260–2282, doi:10.3762/bjoc.21.173
- could be further derivatized (e.g., via borylation, epoxidation), establishing a versatile platform for accessing fused-ring natural products. Substituent-controlled cyclization of 1,n-enynes In transition metal-catalyzed cyclization reactions, the electronic properties and steric hindrance of
The application of desymmetric enantioselective reduction of cyclic 1,3-dicarbonyl compounds in the total synthesis of terpenoid and alkaloid natural products
Beilstein J. Org. Chem. 2025, 21, 2085–2102, doi:10.3762/bjoc.21.164
- underwent dehydration with Martin′s sulfurane to afford the known intermediate 115 [83] and terminal alkene 116 (C12–C13 bond-cleaved byproduct). Thus, the formal total synthesis of (−)-platencin (24) was achieved. On the other hand, epoxidation of 113 followed by acid-mediated regioselective ring-opening
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
Beilstein J. Org. Chem. 2025, 21, 2072–2081, doi:10.3762/bjoc.21.162
- synthesis of (–)-isochaetominine A was increased from 25.4% to 30.8% over five steps. Secondly, a new protocol featuring the use of an aged solution of K2CO3/MeOH to quench the DMDO epoxidation-triggered cascade reaction was developed, which allowed the in situ selective mono- or double epimerization at C11
- aspera chaetominine B. Keywords: epoxidation; selective epimerization; stereodivergent synthesis; structural revision; tandem reaction; Introduction In contemporary organic chemistry, due to the widespread application of modern separation and analytical techniques, the structural elucidation and
- epoxidation-triggered double cyclization reaction. In addition, the synthesis of the recently reported natural products aspera chaetominines A and B (12 and 13) [32] was addressed. Herein, we report the full accounts of these investigations, which include: 1) an improved five-step total synthesis of
Bioinspired total syntheses of natural products: a personal adventure
Beilstein J. Org. Chem. 2025, 21, 2048–2061, doi:10.3762/bjoc.21.160
- , derived from phenylthiol and geranyl bromide, coupled with chiral epoxide 6, prepared through Sharpless epoxidation and TBS protection of 2-methylprop-2-en-1-ol, under strong basic conditions to generate intermediate 7 to further reduce the sulfide moiety with sodium, furnishing diol 8 with the loss of
Enantioselective desymmetrization strategy of prochiral 1,3-diols in natural product synthesis
Beilstein J. Org. Chem. 2025, 21, 1932–1963, doi:10.3762/bjoc.21.151
- . Epoxidation of 131 followed by methylation generated epoxide 132. Construction of the lactone moiety commenced with the oxidative cleavage of the double bond, and the resulting carboxylic acid underwent intramolecular cyclization in the presence of BF3·Et2O to give lactone 133. Subsequent hydride reduction
- ), compound 154 underwent epoxidation followed by acid-mediated cyclization to yield bicyclic compound 155. The synthesis was completed through a nine-step conversion of 155 to obtain (−)-dysiherbaine (156). To construct the asymmetric quaternary carbon centers with an amino group, the Kang group developed a
- into alcohol 170 in nine steps. Subsequent epoxidation of olefin in 170 followed by acid-mediated cyclization provided compound 171 bearing a tetrahydrofuran ring. An eight-step transformation then yielded compound 172. Next, epoxidation of olefin of 172 with Shi’s dioxirane (generated from ketone 173
Oxetanes: formation, reactivity and total syntheses of natural products
Beilstein J. Org. Chem. 2025, 21, 1324–1373, doi:10.3762/bjoc.21.101
- of oxetanes from epoxides using sulphur-stabilised carbanions such as dimethyloxosulphonium methilide (105) or S-methyl-S-(sodiomethyl)-N-(4-tolylsulphonyl)sulphoximine (106) (Scheme 26) [71][72]. Because these reagents are also known to induce epoxidation when reacted with a ketone or aldehyde
Synthetic approach to borrelidin fragments: focus on key intermediates
Beilstein J. Org. Chem. 2025, 21, 1135–1160, doi:10.3762/bjoc.21.91
- alternative route was also proposed for synthesizing 21 from compound 30, which was derived from ent-29. Notably, epoxides 23a and 23b were obtained via Sharpless epoxidation of (E)-2-butenol. Uguen and co-workers began their synthesis by reducing Roche esters 29 and ent-29 to their respective primary
- epoxidation and regioselective reduction to install the hydroxy group at the C3 position [39]. In their retrosynthetic analysis, the target molecule 61 was envisioned to be obtained from epoxide 63 through regioselective opening of the epoxide ring, oxidation of the resulting primary alcohol to a carboxylic
- to a primary alcohol, and then conducting asymmetric epoxidation of the double bond. Evan’s amide 64 would be synthesized from primary alcohol 65 through a sequence of oxidation to aldehyde, Wittig olefination to an unsaturated ester, hydrogenation of the olefin, conversion of the ester to Evans
Recent total synthesis of natural products leveraging a strategy of enamide cyclization
Beilstein J. Org. Chem. 2025, 21, 999–1009, doi:10.3762/bjoc.21.81
- a fragmentation process for the total synthesis of (−)-phlegmariurine B. A one-pot epoxidation/nucleophilic epoxide opening introduced both a hydroxy group and a chloride across the cyclopentene, producing 14 in 57% yield. After oxidation of alcohol 14 to ketone 15, the Mukaiyama hydration then
- reduction, and epoxidation delivered compound 33 with the required oxidation level of the cyclopentane ring. In the final stages, Meinwald rearrangement/hemiketalization in a step-wise procedure, followed by amide reduction, completed the total synthesis of (−)-cephalotine B. Alternatively, after benzylic
Origami with small molecules: exploiting the C–F bond as a conformational tool
Beilstein J. Org. Chem. 2025, 21, 680–716, doi:10.3762/bjoc.21.54
Facile preparation of fluorine-containing 2,3-epoxypropanoates and their epoxy ring-opening reactions with various nucleophiles
Beilstein J. Org. Chem. 2024, 20, 2421–2433, doi:10.3762/bjoc.20.206
- intramolecular interaction between fluorine and metals would also facilitate the smooth progress of these reactions. Such high potential of 1a allowed us to apply it to nucleophilic epoxidation because the resultant epoxyester 2a is recognized as an intriguing building block (Scheme 1). Another expectation to 2a
- usefulness for the epoxidation of the β-CF3-α,β-unsaturated ketones [40], we applied this method at first for the epoxidation of 1b. However, contrary to our anticipation, only a total recovery of the substrate was observed, and further search for an oxidant reached the usage of a NaClO aqueous solution with
- (entries 3 vs 1 and 2). The drawback of this sequence was the isolated yield of 2b no more than 70% which was, at least in part, due to the production of the undesired hydrolyzed products from 1b and/or 2b under the alkaline conditions of this epoxidation reagent. This was experimentally proved by the
Hydrogen-bond activation enables aziridination of unactivated olefins with simple iminoiodinanes
Beilstein J. Org. Chem. 2024, 20, 2305–2312, doi:10.3762/bjoc.20.197
- be unreactive towards sulfonamide (Scheme 4e), suggesting that epoxidation is not on path to the observed aziridines. For discussion of side-products and reaction mass balance, see Figure S4 (Supporting Information File 1). Based on these observations, we favor a mechanism in which H-bond activated
- give rise to epoxidation products. Epoxides are not on-path to the observed aziridines. f) Proposed reaction mechanism. Optimization of HFIP-promoted aziridination of cyclohexene (1a). Conditions: 0.20 mmol 1a, 0.40 mmol PhINTs 2a, 1.0 mL HFIP, N2 atmosphere, 20 °C, 16 h. Yield was determined via 1H
Chemo-enzymatic total synthesis: current approaches toward the integration of chemical and enzymatic transformations
Beilstein J. Org. Chem. 2024, 20, 1693–1712, doi:10.3762/bjoc.20.151
- aldehyde at the C6 sidechain. Furthermore, the fusion protein, JuvD-RhFRED, enabled regio- and diastereoselective epoxidation of the C12 double bond of macrocycles 80–82, culminating in the total synthesis of M-4365 A1 (83), M-4365 A3 (juvenimicin A4, 84), and M-4365 A2 (juvenimicin A3, 85), respectively
Computation-guided scaffold exploration of 2E,6E-1,10-trans/cis-eunicellanes
Beilstein J. Org. Chem. 2024, 20, 1320–1326, doi:10.3762/bjoc.20.115
- implies that protonation and cyclization may be concerted for that conformer (Figure S4, Supporting Information File 1). We previously transformed 2 into the trans,trans-6/6/6-tricyclic C6 alcohol 8 using mCPBA to epoxidize the C6–C7 alkene [7]. Under the same conditions, epoxidation of 1 yielded the 6,7
- with differing configurations at the ring-fused carbons and the 2,3-alkene. Protonation-mediated cyclization of trans- and cis-eunicellanes. (A) The 2E-trans- and 2E-cis-eunicellane skeletons form 6/6/6-tricyclic gersemiene skeletons in the presence of acid. Epoxidation of 1 with mCPBA yields the
Chemoenzymatic synthesis of macrocyclic peptides and polyketides via thioesterase-catalyzed macrocyclization
Beilstein J. Org. Chem. 2024, 20, 721–733, doi:10.3762/bjoc.20.66
- hydroxylation and epoxidation using three P450s (TylI, JuvD and MycCI) involved in the biosynthesis of several different macrolides, eight additional macrolides were achieved from 50, including juvenimicin B1, M-4365 G2, and juvenimicin A3. In the light of this approach, the following bioactive assay
- explored as prospective payloads for antibody-drug conjugation [81][82]. Numerous synthetic approaches have been devised to deliver the cryptophytes skeleton, indicating that the most challenging steps are the regio- and stereospecific macrocyclization and epoxidation [83]. To address these problems, in
- epoxidation with enzymatic macrocyclization in 2020 as shown in Scheme 8 [85]. According to their previous report [86], the production of fragments 61 was initiated by Evans’ asymmetric aldol and alcohol protection to generate 57. Six-step route transformations, including cross metathesis, afforded aldehyde
Production of non-natural 5-methylorsellinate-derived meroterpenoids in Aspergillus oryzae
Beilstein J. Org. Chem. 2024, 20, 638–644, doi:10.3762/bjoc.20.56
- -dependent monooxygenase InsA4. In this engineered pathway, FncE first synthesizes 5-MOA, which then undergoes farnesylation by FncB, methyl ester formation by InsA1, and epoxidation of the terminal olefin in the farnesyl moiety by InsA4 (Figure 2A). Thus, we heterologously expressed the genes encoding these
Recent developments in the engineered biosynthesis of fungal meroterpenoids
Beilstein J. Org. Chem. 2024, 20, 578–588, doi:10.3762/bjoc.20.50
- , FMO EsdpE, which epoxidizes the C-14, C-15 double bond of 13, was employed to produce 19, and the CYC EsdpB cyclizes in a chair–chair–chair conformation to form the 6-6-6 ring structure of 20 [18][19]. This difference in the epoxidation position represents a new point of biosynthetic diversity that
- hydroxy group terminates the cyclization [20][21]. In ascofuranone biosynthesis, compound 21 is initially hydroxylated at C-8, and then the hydroxylated product is cyclized via epoxidation by AscI to form the tetrahydrofuran ring of 23. The biosynthetic pathways of 22 and 23 were elucidated through
- molecular species withdraws a hydrogen atom, and the generated radical induces various reactions such as hydroxylation, unsaturation, epoxidation, halogenation, endoperoxidation, and C–C bond reconstruction, leading to the formation of diverse chemical structures [22][26][27][28][29][30][31]. Structure
Pseudallenes A and B, new sulfur-containing ovalicin sesquiterpenoid derivatives with antimicrobial activity from the deep-sea cold seep sediment-derived fungus Pseudallescheria boydii CS-793
Beilstein J. Org. Chem. 2024, 20, 470–478, doi:10.3762/bjoc.20.42
- II, which could be transferred to III by cyclization and epoxidation. Oxidation and methylation of intermediate III would produce IV. Compounds 1–4 could be obtained by nucleophilic attack at C-8 with the hydroxy or thiol group from IV via intermediate V, followed by oxidation and cyclization
Synthesis of ether lipids: natural compounds and analogues
Beilstein J. Org. Chem. 2023, 19, 1299–1369, doi:10.3762/bjoc.19.96
- tosylation of the primary alcohol produced 4.8. The epoxidation of 4.8 occurred by reaction with t-BuOK in THF, thus producing 4.9 as a chiral electrophile. The regioselective opening of the epoxide is achieved by adding the octadecanol sodium salt. The intermediate was debenzylated by catalytic
- from allyl alcohol (Figure 7) [82]. The Sharpless asymmetric epoxidation of allyl alcohol followed by tosylation produced glycidyl tosylate 7.1a (Figure 7). The reaction of palmityl alcohol (C16H33-OH) in the presence of a catalytic amount of BF3 open regio- and stereoselectively the epoxide to produce
- either sn-1 and sn-2 positions or sn-2 and sn-3 positions [97]. The incorporation of one methylene unit is shown in Figure 13 as an illustration of all these possibilities. But-3-en-1-ol (13.1) was alkylated with bromohexadecane to produce the ether 13.2. The epoxidation of the carbon–carbon double bond
Asymmetric synthesis of a stereopentade fragment toward latrunculins
Beilstein J. Org. Chem. 2023, 19, 428–433, doi:10.3762/bjoc.19.32
- , in view of its coupling to 8. We first relied the chemoselective epoxidation of the homoallylic alcohol, done in presence of VO(OiPr)3 (20 mol %) and t-BuOOH to afford epoxide 13, in 86% yield and a dr of 75:25 (measured by NMR, presumably resulting from the major diastereoisomer of 13; minor isomers
- were not identified), when the reaction was performed at room temperature during 6 hours. This vanadium catalyst superseded VO(acac)2 in terms of yields [26][27]. Additional epoxidation attempts allowed to improve the dr to 82:18 (82% yield) when the reaction was left at −30 °C for 6 days
Combretastatins D series and analogues: from isolation, synthetic challenges and biological activities
Beilstein J. Org. Chem. 2023, 19, 399–427, doi:10.3762/bjoc.19.31
- acetic anhydride followed by epoxidation using m-CPBA gave protected epoxide 50. Subsequent removal of the acetate group using ammonia led to racemic compound 1 (Scheme 8). Rychnovsky and Hwang succeeded in the total syntheses of combretastatin D-2 (2) in a 36% overall yield after 13 steps and
- combretastatin D-1 (1) in 23% overall yield after 16 steps. Later, the same authors performed the enantioselective synthesis of 1 in an attempt to review its absolute configuration [41]. Thus, acetylation of compound 2 followed by the use of Jacobsen’s catalyst [42] to perform the epoxidation of the double bond
- group followed by protection of the obtained alcohol with benzyl bromide provided compound 55, which was subjected to an epoxidation using m-CPBA followed by ring opening using DIBAL [46]. The obtained alcohol was then protected with TBSCl to give fragment 57 (Scheme 10). Using similar conditions to
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