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Search for "overall yield" in Full Text gives 524 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Synthesis of functionalized, 13-alkyl-substituted coralyne derivatives and investigation of their interactions with duplex and abasic site-containing DNA
Beilstein J. Org. Chem. 2026, 22, 1057–1066, doi:10.3762/bjoc.22.84
- a mixture of counter anions PF6− and Cl−. Therefore, the product was converted into its bromide salt by ion exchange chromatography to give coralyne 2e in an overall yield of 70%. Likewise, coralyne 2d was functionalized with an aminooxyalkyl linker [37] by PyBOP-assisted coupling and ion metathesis
Synthesis of sterically shielded piperidine nitroxides via acid-catalyzed heterocyclization of β-aminoketone derivatives with ketones
Beilstein J. Org. Chem. 2026, 22, 948–954, doi:10.3762/bjoc.22.74
- formation, and hydrazinolysis (Scheme 1). The target 2-(2-aminoalkyl)-1,3-dioxolanes 4a,b were obtained in pure form after vacuum distillation. Conversion of α,β-unsaturated ketones 1a,b to aminodioxolanes 4a,b proceeded in 49% and 69% overall yield, respectively. In the 1H NMR spectrum of 4a
- nitroxides 7a–d in 50–80% overall yield from piperidines 5a,b (Scheme 3). The structures of nitroxides 7a–d were confirmed by 1H NMR spectroscopy of their amine derivatives, obtained via Zn/CF3COOH reduction in CD3OD, following a reported procedure [37]. The full line-shape analysis of the 1H NMR spectra for
Synthesis of depressin, cryptomeridiol and 4-epi-cryptomeridiol enabled by a terpenoid chiral pool-producing platform
Beilstein J. Org. Chem. 2026, 22, 683–690, doi:10.3762/bjoc.22.53
- -butylammonium fluoride (TBAF) for TBS ether removal, followed by DMP for hydroxy group oxidation, delivering the desired product 1 in 29% overall yield in three steps from 14a/b, together with a double bond-isomerized product 15 in 39% overall yield after HPLC purification. The configuration of C12–C13 double
Modern synthetic pathways towards eribulin and its subunits
Beilstein J. Org. Chem. 2026, 22, 495–526, doi:10.3762/bjoc.22.37
- overall yield (17.6% vs 9.3%). Also, the ketalization from 183 to 184 was enhanced. Here, the application of a continuous flow process and the recovery of (R)-184 led to an increasement of yield in 6.7% in comparison to the former approach. It is also important to mention that Nicolaou and co-workers
- rearrangement via allene 269 and cyclization towards 2,5-dihydrofuran 270. Cleavage of the Bz-moiety and tautomerization to ketone 271 enabled the unmasking of the methylene motif of 272 via Wittig reaction. In this convergent synthesis, a remarkable overall yield of 17.6% for 272 was obtained, which makes it a
- sequence of 12 steps, which only included the use of cheap materials and preparatively simple transformations. Therefore, if the overall yield can be increased even further, this synthesis represents a useful alternative to existing pathways. Conclusion In summary, numerous advancements were made in the
Dialkylaminoalkylation of β-ketosulfones via ring-opening of 3-sulfonylpyrrolidines
Beilstein J. Org. Chem. 2026, 22, 383–389, doi:10.3762/bjoc.22.26
- cesium carbonate at 25 °C for 96 h provided higher yield (Table 1, entry 2, 70%). However, heating this mixture at 65 °C for 24 h in a sealed vial gave pure desired 4-methoxy-N,N-dimethyl-3-(phenylsulfonyl)butan-1-amine (4a) in 90% yield and 83% overall yield starting from ketosulfone 1a (Table 1, entry
Synthesis of tricyclic fused pyrrolidine nitroxides from 2-alkynylpyrrolidine-1-oxyls
Beilstein J. Org. Chem. 2026, 22, 344–351, doi:10.3762/bjoc.22.22
- acetoxy groups and reduction of the nitroxyl fragment to the corresponding hydroxylamine. Primary products were stirred with a solution of NaOH in methanol under aerobic conditions to achieve complete hydrolysis and regeneration of the nitroxide group. Pyrazole 9a was isolated with an overall yield of 33
A mild and atom-efficient four-component cascade strategy for the construction of biologically relevant 4-hydroxyquinolin-2(1H)-one derivatives
Beilstein J. Org. Chem. 2026, 22, 244–256, doi:10.3762/bjoc.22.18
- quantitatively. Although the two-step sequence generally performed well, isolation of malonamides 1a–c was associated with significant material loss, impacting the overall yield. To address this, a one-pot synthesis directly from anilines was developed, avoiding isolation of intermediates. After approximately 4
A new synthesis of Tyrian purple (6,6’-dibromoindigo) and its corresponding sulfonate salts
Beilstein J. Org. Chem. 2026, 22, 167–174, doi:10.3762/bjoc.22.10
- , known as Tyrian purple. In this work, we report a new strategy for the synthesis of 6,6’-dibromoindigo in four steps from p-bromotoluene in 14.5% overall yield. A key improvement in the reported synthesis is the oxidation of the benzylic methyl group of 4-bromo-2-nitrotoluene to 4-bromo-2
- of associated waste disposal or the lengthy conversion involving the formation and hydrolysis of a nitrone [7][8][9][13][14][15][16][17]. When compared to other published syntheses of 1, the overall yield is reasonable, although others have reported strategies with higher yields. For example, Imming
Total synthesis of natural products based on hydrogenation of aromatic rings
Beilstein J. Org. Chem. 2026, 22, 88–122, doi:10.3762/bjoc.22.4
- rearrangement and Lewis acid-promoted acetal–ene reaction provided the tetracyclic skeleton 101. With 101 in hands, a 6 step transformation afforded the alkyne 102 in an overall yield of 45%. After obtaining 102, the authors used a free radical reaction to initiate a one-step 6-exo-trig cyclization
- was then hydrogenated to the piperidine by direct hydrogenation, and the benzene ring was then reduced to an unsaturated ketone structure by Birch reduction, completing the highly efficient total synthesis of GB13 in 6 steps with an overall yield of 10%. Total synthesis of (±)-corynoxine and
- . Three subsequent steps (74% overall yield) then provided the key hydrogenation precursor 161. Hydrogenation of 161 under heterogeneous catalytic conditions (Pd/C, Pt/C, Raney Ni, Rh/C, Ru/C) proved inefficient, giving complex mixtures that included partially or fully hydrogenated pyridines, over-reduced
Synthesis and applications of alkenyl chlorides (vinyl chlorides): a review
Beilstein J. Org. Chem. 2026, 22, 1–63, doi:10.3762/bjoc.22.1
- significantly influenced the overall yield. The decline in yield over time can potentially be attributed to polymerization side reactions of product 9 under the reaction conditions. Visual evidence of polymerization included difficulty in cleaning the reaction flask and the formation of solid polymer deposits
Total synthesis of asperdinones B, C, D, E and terezine D
Beilstein J. Org. Chem. 2025, 21, 2730–2738, doi:10.3762/bjoc.21.210
- acetic acid [59] afforded asperdinones 1–4 in an average overall yield of 14% via the allylation/cross metathesis route and 7% via the direct prenylation route. In all cases, spectroscopic and analytical data were in accordance with the literature. The moderate yield in the Negishi cross-coupling
- Fmoc-ʟ-alanine gave 41 which was subjected to a cross-metathesis reaction with the Grubbs II catalyst, then deprotection to give terezine D (6) in 44% overall yield. Application of the same protocol using isatoic anhydride led to ent-asperdinone E (43) in 13% overall yield. It is interesting that the
- . Asperidinones 1–4 were obtained in 7% average yields via the direct prenylation route, and 14% from the allylation/cross-metathesis route, whereas terezine D (6) was isolated in 44% overall yield. Insights into the reactivity and stability of the iodozinc N-Fmoc-ᴅ-alanyl anthranilamide reagent derived from 29
Competitive cyclization of ethyl trifluoroacetoacetate and methyl ketones with 1,3-diamino-2-propanol into hydrogenated oxazolo- and pyrimido-condensed pyridones
Beilstein J. Org. Chem. 2025, 21, 2716–2729, doi:10.3762/bjoc.21.209
- a microwave (MW) reactor (Table 1, entry 6). It turned out that after 24 hours of heating the complete conversion of oxo ester 1 occurred and the overall yield increased to 83% (Table 1, entry 5), whereas the use of MW reduced the reaction time down to five hours (Table 1, entry 6), but the contents
- triethylamine in 1,4-dioxane (Table 1, entry 9) did not affect the reaction course significantly. The use of conditions with catalysis by a combination of Bronsted acid and base (acetic acid, Et3N) contributed to a shift in the reaction selectivity towards octahydropyridopyrimidinones 4 (overall yield 71
Recent advancements in the synthesis of Veratrum alkaloids
Beilstein J. Org. Chem. 2025, 21, 2657–2693, doi:10.3762/bjoc.21.206
- (total steps: 22, overall yield 1.4%) and provided the first total synthesis of this molecule (in comparison to the Giannis group, who achieved the first synthesis of cyclopamine in a semisynthetic fashion). We already discussed a possible disconnection through the D-ring and late-stage formation of the
- in 23 steps in the LLS, with a total step count of 31 (overall yield 0.2%). Albeit being significantly longer in the sequence than the reported synthesis of the Baran group [23], this approach provides an entirely different strategy and also displays new methodologies (asymmetric hydrogenation
- , reduction of the lactam furnished cyclopamine (6) in 65% yield over two steps. The reported semisynthesis of the Liu/Qin group displays the shortest route to cyclopamine with 13 steps in the LLS, 15 steps in total and an overall yield of 3.6%. Jervine For the C11-oxidized analogue of cyclopamine, jervine
Recent advances in total synthesis of illisimonin A
Beilstein J. Org. Chem. 2025, 21, 2571–2583, doi:10.3762/bjoc.21.199
- , albeit with a lower overall yield of 3%. Yang’s bioinspired synthesis of illisimonin A In 2023, Yang and co-workers reported a bioinspired divergent synthesis of illisimonin A and merrilactone A, which belonged to illisimonane-type and anislactone-type Illicium sesquiterpenes, respectively [30]. They
Ni-promoted reductive cyclization cascade enables a total synthesis of (+)-aglacin B
Beilstein J. Org. Chem. 2025, 21, 2548–2552, doi:10.3762/bjoc.21.197
- 2,4,4,6-tetrabromo-2,5-cyclohexadienone (TBCD) in CH2Cl2 followed by reaction with allyl alcohol, provided β-bromo acetal 5 in 30% overall yield starting from alcohol 6. With a successful preparation of the cyclization precursor 5, the designed nickel-promoted reductive tandem cyclization was pursued
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
- available (+)-sclareolide (101) as starting compound, from which key alcohol 102 was synthesized in 7 steps. Selective mesylation of the secondary alcohol in 102 followed by semipinacol rearrangement catalyzed by t-BuOK afforded diketone 104 as a pair of epimers at C12 in a 1:1 ratio, with 70% overall yield
- unseparated mixture of abeolupanes 245 and 246, in a ratio of 1.5–3:1, with a total yield of 89%. The interaction of compound 243 with BF3·Et2O in benzene at 70 °C gave a mixture of olefins 245 and 246 in a 1:2 ratio, with an overall yield of 88%. Similar transformations were carried out with methyl
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
- bonds of 83 (Scheme 10). Building block 76 was first obtained in 18% overall yield from β-ketoester 74 through a sequence involving Michael addition, decarboxylation, nitrile hydration, and cyclization under vacuum. Aminoketal 81 – a direct precursor to the oxygen-sensitive α,β-unsaturated iminium 81a
- room temperature, delivering spiroacetal (S)-114 with complete retention of configuration (>99% ee). The subsequent one-pot acetylation generated (S)-115 in 83% overall yield over three steps from (S)-112. The following functional group manipulations of (S)-115 – including debenzylation/debromination
Halogenated butyrolactones from the biomass-derived synthon levoglucosenone
Beilstein J. Org. Chem. 2025, 21, 2297–2301, doi:10.3762/bjoc.21.175
- been reported in a 12-step procedure starting with glucose in an overall yield of 2% [24]. Enol esters [25], enolates [26], enamines [27][28], and silyl enol ethers [29], some of which can be derived from LGO, have been used in electrophilic fluorination and trifluoromethylation strategies. It was
C2 to C6 biobased carbonyl platforms for fine chemistry
Beilstein J. Org. Chem. 2025, 21, 2103–2172, doi:10.3762/bjoc.21.165
- alkane fuels (bicyclopentane, tricyclic alkane and spirocyclic alkane) through hydrodeoxygenation [205][206][207][208][209][210]. A cycloalkane with a density of 0.89 g/cm3 and a freezing point below −60 °C was prepared from CPN and lignin-derived vanillin. An overall yield of 95.2% of mono- and di
- ][80][81]. Keto acetals have been observed as by-products, such as in the work reported by Gupta investigating the acid-catalyzed reactions of DHA with various alcohols (Scheme 17) [82]. Colbran and colleagues reported the conversion of DHA to dihydroxyacetone phosphate in four steps in 27% overall
- yield [83]. In their synthesis the cyclic acetal (2,5-diethoxy-1,4-dioxane-2,5-diyl)dimethanol or its dimethoxy analog was esterified with diphenyl phosphorochloridate in pyridine to give (2,5-diethoxy-1,4-dioxane-2,5-diyl)bis(methylene) tetraphenyl bis(phosphate). Subsequent removal of the phenyl
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
- secondary alcohol to a ketone allowed for rapid construction of bicyclic ketone 34 in high overall yield. The oxidative dehydrogenation of 34 gave α,β-unsaturated bicyclic ketone 35 smoothly. Sequential A-ring construction and functional group modifications of 35 produced the diketone 36. Subsequently, 36
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
- generation of our synthetic strategy to chaetominine-type alkaloids featuring two modifications of the last step of our 4 to 6-step approach. Firstly, by employing EDCI/HOBt as the coupling system for the last step of the one-pot O-debenzylation–lactamization reaction, the overall yield of our previous total
- compound 14, an intermediate in our synthesis of (–)-isochaetominine A (4) [63]. Indeed, EDCI/HOBt-mediated lactamization of 14 derived amino acid (not shown) via debenzylation increased the yield of (–)-isochaetominine A (4) from 75% to 91% (Scheme 1). Thus, overall yield of the total synthesis of
Asymmetric total synthesis of tricyclic prostaglandin D2 metabolite methyl ester via oxidative radical cyclization
Beilstein J. Org. Chem. 2025, 21, 1964–1972, doi:10.3762/bjoc.21.152
- synthesis of tricyclic-PGDM methyl ester in 9 steps and 8% overall yield. Keywords: asymmetric total synthesis; oxidative radical cyclization; tricyclic prostaglandin D2 metabolite methyl ester; Introduction Prostaglandins (PGs), a family of hormone-like lipid compounds, are ubiquitous natural products
- synthesis of 4 was unsatisfactory because it required nine steps to prepare bicyclic intermediate 25 with an overall yield of just 2.0%. This low efficiency prompted us to develop a more streamlined synthetic route for target compound 4. Second generation asymmetric total synthesis of tricyclic-PGDM methyl
- ] to provide compound 4 in 8% overall yield over 9 steps starting from the readily available compound 16 [41]. Conclusion In conclusion, we developed a synthetic strategy using a radical Csp3–H cyclization, including Snider oxidative radical cyclization and photoredox-catalyzed radical cyclization, to
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
- adopted using compound 85 as the synthetic intermediate, which was prepared from diol 77 in a four-step sequence with 60% overall yield and 96% ee. In 2003, the Fukuyama group realized the first total synthesis of leustroducsin B, a microbial metabolite with various biological activities, featuring a
Convenient alternative synthesis of the Malassezia-derived virulence factor malassezione and related compounds
Beilstein J. Org. Chem. 2025, 21, 1730–1736, doi:10.3762/bjoc.21.135
- -protected malassezione, which upon deprotection yields malassezione in an overall yield of ca. 20%. This is an improvement over the preparation of the isonitrile followed by an Fe hydride initiated isonitrile–olefin intramolecular coupling reaction, which generated malassezione with an overall yield of ca
- [20], or, more recently, (iii) prepared via an Fe hydride initiated isonitrile–olefin intramolecular coupling reaction (Scheme 1A) [18]. The reported synthetic route relies on an initial 4-step preparation of the isonitrile precursor, which was accomplished in an overall yield of ca. 14%. The
- derivative was easily removed with aqueous washes, thereby obviating the need for column purification to remove the more hydrophobic dicyclohexylurea obtained when DCC was employed to facilitate the reaction. Subsequent removal of the Boc groups with TFA furnished malassezione (1) in an overall yield of ca
Chemical synthesis of glycan motifs from the antitumor agent PI-88 through an orthogonal one-pot glycosylation strategy
Beilstein J. Org. Chem. 2025, 21, 1587–1594, doi:10.3762/bjoc.21.122
- desired phosphite, which was further oxidized by 3-chloroperoxybenzoic aicd (mCPBA) at −78 °C to 0 °C, producing the desired phosphorylated fully protected trisaccharide 12 in 79% overall yield over three steps. Removal of all protecting groups in trisaccharide 12 is a challenging task due to the presence
- all Bz groups with 1 M NaOH (dioxane/MeOH/H2O, room temperature). The monophosphorylated trisaccharide 1 was obtained in 60% overall yield over two steps from 12 after purification over a SephadexTM LH-20 column. It was noted that the switch of deprotection sequences (first Bz groups, second Bn and
- all Bz groups with 1 M NaOH successfully produced monophosphorylated tetrasaccharide 2 in 63% overall yield. One-pot synthesis of glycans 3 and 4 Furthermore, we investigated the synthesis of monophosphorylated pentasaccharide 3 (Scheme 3). Orthogonal one-pot glycosylation of Man PTFAI 6 (1.2 equiv
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