Experimental and DFT studies on the regioselective methanolysis of 5-azido-9-oxabicyclo[6.1.0]nonan-4-yl 4-nitrobenzoate isomers

• İlknur Polat,
• Selçuk Eşsiz and
• Emine Salamci

Beilstein J. Org. Chem. 2026, 22, 547–556, doi:10.3762/bjoc.22.40

• regioselective methanolysis of new azido-4-nitrobenzoate epoxycyclooctane isomers and the characterization of the resulting products are described herein. Firstly, treatment of key compound 8-azidocyclooct-4-en-1-ol with 4-nitrobenzoyl chloride followed by an epoxidation reaction and then methanolysis of the

• epoxide ring and acetylation resulted in the formation of two corresponding chloro-acetate isomers. The structure of one of the chloro-acetate isomers was determined via crystallographic analysis and the other by 1D and 2D NMR spectroscopy. DFT computations confirm the regioselectivity of the methanolysis

• process, highlighting its precision and efficiency. Keywords: azides; 8-azidocyclooct-4-en-1-yl 4-nitrobenzoate; DFT; epoxycyclooctane azide; methanolysis; Introduction Organic azides are very important precursors for the preparation and synthesis of various nitrogen-containing compounds, as well as

Approaches to stereoselective 1,1'-glycosylation

• Daniele Zucchetta and
• Alla Zamyatina

Beilstein J. Org. Chem. 2025, 21, 1700–1718, doi:10.3762/bjoc.21.133

• subsequent basic anhydrous methanolysis yielding the β-configured GlcN-lactol 82 [103]. Glycosylation with the trichloroacetimidate donor 84 was carried out at a reduced temperature of −65 °C to suppress lactol anomerization, ultimately affording the β,β-configured 1,1'-diglucosamine 112. β,β-1,1

Enantioselective synthesis of β-aryl-γ-lactam derivatives via Heck–Matsuda desymmetrization of N-protected 2,5-dihydro-1H-pyrroles

• Arnaldo G. de Oliveira Jr.,
• Martí F. Wang,
• Rafaela C. Carmona,
• Danilo M. Lustosa,
• Sergei A. Gorbatov and
• Carlos R. D. Correia

Beilstein J. Org. Chem. 2024, 20, 940–949, doi:10.3762/bjoc.20.84

• presence of a methoxy group after the Heck–Matsuda reaction indicates methanolysis after arylation. Given the importance of the lactam rings, we envisioned a sequential Jones oxidation protocol without isolation of the methyl N,O-acetal products to obtain the corresponding lactams 4. As observed in

• methanolysis, the hemiaminal ether product 3 is formed. We hypothesize that the enantioselectivity-determining step consists of the migratory insertion of the aryl group bonded to palladium to the pyrroline. The steric effect of the t-Bu group favors the coordination of the pyrroline with the protecting group

Linker, loading, and reaction scale influence automated glycan assembly

• Marlene C. S. Dal Colle,
• Manuel G. Ricardo,
• Nives Hribernik,
• José Danglad-Flores,
• Peter H. Seeberger and
• Martina Delbianco

Beilstein J. Org. Chem. 2023, 19, 1015–1020, doi:10.3762/bjoc.19.77

• excellent purity in all experiments (Figures 2D, 3C, and Figures S8 and S9 in Supporting Information File 1). For these compounds, we explored two different post-AGA procedures: the standard path A based on photocleavage and HPLC purification, and path B involving on resin methanolysis of the ester groups

• , photocleavage, hydrogenolysis of the remaining PGs, and purification (Figure 2C). The latter is commonly employed for compounds synthesized on L2 because of the poor stability of free-reducing glycans in basic conditions needed for the methanolysis step [33]. The isolated yields of the fully protected compound

Regioselective synthesis of methyl 5-(N-Boc-cycloaminyl)-1,2-oxazole-4-carboxylates as new amino acid-like building blocks

• Jolita Bruzgulienė,
• Greta Račkauskienė,
• Aurimas Bieliauskas,
• Vaida Milišiūnaitė,
• Miglė Dagilienė,
• Gita Matulevičiūtė,
• Vytas Martynaitis,
• Sonata Krikštolaitytė,
• Frank A. Sløk and
• Algirdas Šačkus

Beilstein J. Org. Chem. 2022, 18, 102–109, doi:10.3762/bjoc.18.11

• Meldrum’s acid in the presence of EDC·HCl and DMAP, followed by methanolysis of the corresponding adducts [27][28][31][36][37][38]. Reaction of the resulting β-keto esters 2a–h with N,N-dimethylformamide dimethylacetal afforded cycloaminyl β-enamino ketoesters 3a–h. After isolation of compounds 3a–h from

α-Ketol and α-iminol rearrangements in synthetic organic and biosynthetic reactions

• Scott Benz and
• Andrew S. Murkin

Beilstein J. Org. Chem. 2021, 17, 2570–2584, doi:10.3762/bjoc.17.172

• . Subsequent methanolysis yields α-hydroxy-β-ketoamide 23 (Figure 6). The overall reaction occurs diastereospecifically, with greater than 80% yield across each of 5 distinct amide derivatives [8]. Tandem α-ketol rearrangements Because α-ketol rearrangements can be initiated by simple reagents like a Brønsted

Strategies for the synthesis of brevipolides

• Yudhi D. Kurniawan and
• A'liyatur Rosyidah

Beilstein J. Org. Chem. 2021, 17, 2399–2416, doi:10.3762/bjoc.17.157

• -promoted intramolecular oxacyclization. After TBS protection, intermediate 32 was collected in 86% yield from epoxide 30. Basic methanolysis of the cyclic carbonate followed by treatment with NaH and N-tosylimidazole then afforded terminal epoxide 34 in 97% yield. Unfortunately, attempts to open the

• using DDQ to form alcohol 40. At this point, the stereogenic center at the C6’ carbon required an inversion to match the target molecule. Thus, a standard Mitsunobu procedure followed by basic methanolysis were conducted. The desired inverted product 16, however, did not form. The authors hypothesized a

Progress and challenges in the synthesis of sequence controlled polysaccharides

• Giulio Fittolani,
• Theodore Tyrikos-Ergas,
• Denisa Vargová,
• Manishkumar A. Chaube and
• Martina Delbianco

Beilstein J. Org. Chem. 2021, 17, 1981–2025, doi:10.3762/bjoc.17.129

A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

• Guido Gambacorta,
• James S. Sharley and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90

Valorisation of plastic waste via metal-catalysed depolymerisation

• Francesca Liguori,
• Carmen Moreno-Marrodán and
• Pierluigi Barbaro

Beilstein J. Org. Chem. 2021, 17, 589–621, doi:10.3762/bjoc.17.53

• ), bis(2-hydroxyethyl)terephthalate (BHET), terephthalamides (TPM [171]) and EG (Figure 3). Catalytic hydrogenolysis, hydrolysis, methanolysis and glycolysis reactions of (postconsumer) PET have been reviewed, each showing their own advantages and disadvantages [172][173]. For instance, glycolysis

• usually requires more problematic purifications than methanolysis, which, on the other hand, is generally more energy-intensive. Some solvolytic processes of PET are already in operation at the industrial or pilot scale [174][175]. However, they often rely on the use of considerable amounts of strong

• depolymerisation of PET was achieved using zinc acetate as catalyst in hot compressed water [195]. A TPA yield of 90.5% was obtained at 240 °C after 30 min reaction time, using a ZnAc2/PET weight ratio as low as 0.015. For this, a mechanism was speculated in which proton ions act as activators. Methanolysis. To

Menthyl esterification allows chiral resolution for the synthesis of artificial glutamate analogs

• Kenji Morokuma,
• Shuntaro Tsukamoto,
• Kyosuke Mori,
• Kei Miyako,
• Ryuichi Sakai,
• Raku Irie and
• Masato Oikawa

Beilstein J. Org. Chem. 2021, 17, 540–550, doi:10.3762/bjoc.17.48

• (rac)-16 (87% yield), followed by alkaline methanolysis (74% yield) [17] and Pinnick oxidation (43% yield) [18][19][20], delivered carboxylic acid (rac)-19. Unfortunately, an attempt to improve the oxidation yield was not fruitful; the oxidation of aldehyde (rac)-18 with TEMPO [21] resulted in a lower

Progress in the total synthesis of inthomycins

• Bidyut Kumar Senapati

Beilstein J. Org. Chem. 2021, 17, 58–82, doi:10.3762/bjoc.17.7

• [53][54][55] using quinidine TMS ether (TMSQD), LiClO4, and Hünig’s base. The aldehyde (Z)-78 was obtained from propargyl alcohol 14 via (Z)-iodo alcohol 15a. The β-lactone (+)-79a was converted to enantioenriched vinyl iodides (+)-84 and 85a separately. Thus, methanolysis of (+)-79a provided (–)-80a

Recent synthesis of thietanes

• Jiaxi Xu

Beilstein J. Org. Chem. 2020, 16, 1357–1410, doi:10.3762/bjoc.16.116

Automated glycan assembly of arabinomannan oligosaccharides from Mycobacterium tuberculosis

• Alonso Pardo-Vargas,
• Priya Bharate,
• Martina Delbianco and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2019, 15, 2936–2940, doi:10.3762/bjoc.15.288

• methanolysis, followed by Pd/C-catalyzed hydrogenolysis of the carboxybenzyl group and the benzyl ethers. Mannosides 4–6 were deprotected and purified using reversed-phase HPLC to obtain fully deprotected mannosides 10–12 (Figure 2). For the arabinomannosides 7–9, the acid-labile arabinose chain was cleaved

A review of asymmetric synthetic organic electrochemistry and electrocatalysis: concepts, applications, recent developments and future directions

• Munmun Ghosh,
• Valmik S. Shinde and
• Magnus Rueping

Beilstein J. Org. Chem. 2019, 15, 2710–2746, doi:10.3762/bjoc.15.264

• chiral auxiliary ([92]. The authors established that the Mannich addition occurred exclusively on the Si-face of the N-acyliminium ions, resulting in the threo-isomer as the major isomer (with moderate yields and good diastereomeric ratios). Upon catalytic hydrogenation followed by methanolysis, threo

Application of chiral 2-isoxazoline for the synthesis of syn-1,3-diol analogs

• Juanjuan Feng,
• Tianyu Li,
• Jiaxin Zhang and
• Peng Jiao

Beilstein J. Org. Chem. 2019, 15, 1840–1847, doi:10.3762/bjoc.15.179

• NaIO4 yielded the carboxylic acid 14 in 86% yield [70], which was reacted with Boc2O to get the tert-butyl ester 15 [26][43][71]. The ee of 15 was determined as 74%. The racemic sample of 15 was prepared from racemic diethyl malate following known methods [26][27]. Finally, K2CO3-catalyzed methanolysis

• well tolerate PTSA-catalyzed methanolysis. Conclusion In conclusion, we synthesized tert-butyl (3S,5R)-6-hydroxy-3,5-O-isopropylidene-3,5-dihydroxyhexanoate (16), which is enantiomeric to a key intermediate for atorvastatin, from a chiral 2-isoxazoline (3). The β-hydroxy ketone 7 obtained from 3 could

Different reactivity of phosphorylallenes under the action of Brønsted or Lewis acids: a crucial role of involvement of the P=O group in intra- or intermolecular interactions at the formation of cationic intermediates

• Stanislav V. Lozovskiy,
• Alexander Yu. Ivanov and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2019, 15, 1491–1504, doi:10.3762/bjoc.15.151

• and 2, Table 2). On the other hand, 1 equivalent of AlCl3 is not enough to activate allene 1a; thus, under these conditions, only acid 2 was obtained as a product of the hydrolysis of starting compound 1a (Table 2, entry 3). Methanolysis of the reaction mixture gave diene E-10b (Table 2, entry 7). The

• -pot synthesis of indane 12d starting from 2-methylbut-3-yn-2-ol (Scheme 7, see procedure in Supporting Information File 1). The first stage of this procedure gave allene 1a, which was dissolved in CH2Cl2 and subjected to reaction with p-xylene under the action of AlCl3. Finally, methanolysis of the

• -10a. Whereas, in the presence of an arene, cation 16 reacts with it leading to species 17. The latter can be protonated with the formation of cation 18. This species may react in two different ways. The first option is it could lead to alkene 19 and finally to compounds 11 upon methanolysis of the

Syntheses and chemical properties of β-nicotinamide riboside and its analogues and derivatives

• Mikhail V. Makarov and
• Marie E. Migaud

Beilstein J. Org. Chem. 2019, 15, 401–430, doi:10.3762/bjoc.15.36

•  4). The reaction between Nam (1a) and 1,2,3,5-tetra-O-acetyl-β-D-ribofuranose (2a) in acetonitrile at room temperature resulted in the corresponding triacetate derivative of NR+ triflate (OTf−) 9a which was converted without isolation into NR+OTf− by methanolysis. The final N-glycoside contained 13

Synthesis of nonracemic hydroxyglutamic acids

• Dorota G. Piotrowska,
• Iwona E. Głowacka,
• Andrzej E. Wróblewski and
• Liwia Lubowiecka

Beilstein J. Org. Chem. 2019, 15, 236–255, doi:10.3762/bjoc.15.22

• -hydroxy-L-glutamic acid derivative 66 (Scheme 16) was required and it was obtained as a single diastereoisomer from 65 in the same way [75][76]. By bromination of L-glutamic acid Bromination of N-phthaloyl-L-glutamic acid [(S)-67] followed by methanolysis gave a 2:1 mixture of threo and erythro

• cleanly liberates (2S,3S,4S)-4 (Scheme 25) [100]. This methodology opens the way to (3S,4S)-3-hydroxy-4-methoxy- (104) and 3,4-dimethoxy-L-glutamic acid (105) since selective opening of the lactone ring in 95 can be accomplished by boron trifluoride etherate-catalyzed methanolysis at low temperatures to

Selective ring-opening metathesis polymerization (ROMP) of cyclobutenes. Unsymmetrical ladderphane containing polycyclobutene and polynorbornene strands

• Yuan-Zhen Ke,
• Shou-Ling Huang,
• Guoqiao Lai and
• Tien-Yau Luh

Beilstein J. Org. Chem. 2019, 15, 44–51, doi:10.3762/bjoc.15.4

• further ROMP of the norbornene appended polycyclobutene in the presence of Grubbs first generation catalyst in DCM at ambient temperature. Methanolysis of this unsymmetrical ladderphane gives polycyclobutene methyl ester and insoluble polynorbornene-amide-alcohol. The latter is converted into the

• spectrum of 8 shows that the relative intensity of the signals around δ 5.4 ppm was doubled, all signals due to olefinic protons in 9 and 14 being diminished. Methanolysis of unsymmetrical ladderphane 8 In order to confirm the uniformity of the polymerization leading to the formation of unsymmetrical

• ladderphane 8, methanolysis of 8 with NaOMe in methanol at rt gave 7 and 18. Chloroform was then added and 18 was collected as a grayish precipitate in 56% yield. After filtration, the filtrate was worked up to afford 7 in 64% yield with a degree of polymerization of 10 (Mn = 2500, PDI = 1.11), in good

Mechanochemistry of nucleosides, nucleotides and related materials

• Olga Eguaogie,
• Joseph S. Vyle,
• Patrick F. Conlon,
• Manuela A. Gîlea and
• Yipei Liang

Beilstein J. Org. Chem. 2018, 14, 955–970, doi:10.3762/bjoc.14.81

• and subsequent Boc-protection were both performed in the absence of solvent under mechanochemical conditions. In situ methanolysis of the TMS ethers yielded the corresponding base-protected nucleosides. The opaque nature of typical reaction vessels used in ball milling has enabled cleaner reactions of

Phosphodiester models for cleavage of nucleic acids

• Satu Mikkola,
• Tuomas Lönnberg and
• Harri Lönnberg

Beilstein J. Org. Chem. 2018, 14, 803–837, doi:10.3762/bjoc.14.68

Investigations towards the stereoselective organocatalyzed Michael addition of dimethyl malonate to a racemic nitroalkene: possible route to the 4-methylpregabalin core structure

• Denisa Vargová,
• Rastislav Baran and
• Radovan Šebesta

Beilstein J. Org. Chem. 2018, 14, 553–559, doi:10.3762/bjoc.14.42

• amine 9 to compound 11 in two steps. However, under microwave heating conditions, both couplings of the amino group with squarate, as well as methoxymethyl (MOM) deprotection was observed. To the best of our knowledge, there is no report describing methanolysis of MOM-groups under microwave conditions

Novel amide-functionalized chloramphenicol base bifunctional organocatalysts for enantioselective alcoholysis of meso-cyclic anhydrides

• Lingjun Xu,
• Shuwen Han,
• Linjie Yan,
• Haifeng Wang,
• Haihui Peng and
• Fener Chen

Beilstein J. Org. Chem. 2018, 14, 309–317, doi:10.3762/bjoc.14.19

• great utility of chloramphenicol base scaffold in industrial production of enantiopure compounds is the synthesis of a precursor of biotin (vitamin H) by the chloramphenicol base-promoted asymmetric methanolysis of meso-cyclic anhydrides [41][42][43]. Despite extensive studies on chloramphenicol-base

• chloramphenicol-derived bifunctional amide organocatalysts and their application for enantioselective alcoholysis of meso-cyclic anhydrides. In the precedented urea- or thiourea-based organocatalytic methanolysis of anhydrides, one big problem is the homo-aggregation of the catalysts via hydrogen bonding, which

• , entries 20–23). These results implicated that there is no significant aggregation of catalysts in this system. This bifunctional Brønsted acid/base catalyst 7i proved to be highly active toward asymmetric methanolysis of various meso-cyclic anhydrides. As shown in Table 2, various cyclic anhydrides were

Aminosugar-based immunomodulator lipid A: synthetic approaches

• Alla Zamyatina

Beilstein J. Org. Chem. 2018, 14, 25–53, doi:10.3762/bjoc.14.3