Synthetic approach to borrelidin fragments: focus on key intermediates

• Yudhi Dwi Kurniawan,
• Zetryana Puteri Tachrim,
• Teni Ernawati,
• Faris Hermawan,
• Ima Nurasiyah and
• Muhammad Alfin Sulmantara

Beilstein J. Org. Chem. 2025, 21, 1135–1160, doi:10.3762/bjoc.21.91

• 94% yield. Like 40, iodination of ent-40 gave crystalline product ent-42, and its structure was confirmed by XRD crystallography. The intermediate ent-40 was then subjected to the same tosylation/thiolation/oxidation sequence used for the 40 to 41 conversion, yielding ent-41 in comparable yield (82

• intermediate 20 in 98% yield. The authors highlighted that shifting the epoxides from 23a,b to 46a,b resulted in the additional tosylation/reduction sequence to install the C4 and C10 methyl moieties of the desired target molecule, making the overall synthesis more lengthy. Thus, 20 was obtained from ent-29

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

• -amine reduction and tosylation from diethyl (S)-2-(hex-5-en-2-yl)malonate ((S)-6). The stereocenter in geminal ester (S)-6 could be derived from (R)-2-methyloxirane ((R)-2) via a ring-opening reaction and a stereospecific inversion of the chiral secondary tosylate (R)-5. Following the similar procedure

• oxidation. The optical purity of the chiral secondary alcohol (R)-4 was more than 99% ee, determined by 1H NMR spectrum of its Mosher ester [27][28]. The subsequent tosylation with p-tosyl chloride gave (R)-hex-5-en-2-yl 4-methylbenzenesulfonate ((R)-5) in 88% yield [29]. The reaction of (R)-5 with the

• , geminal acid (S)-7 was decarboxylated with DMSO to yield chiral acid (S)-8 [33], followed by TiCl4-catalyzed reduction with ammonia-borane to obtain the chiral alkenyl alcohol (S)-9 [34]. The final tosylation with p-tosyl chloride provided (S)-3-methylhept-6-en-1-yl 4-methylbenzenesulfonate ((S)-10) [29

Cyclodextrin-based rotaxanes for polymer materials: challenge on simultaneous realization of inexpensive production and defined structures

• Yosuke Akae

Beilstein J. Org. Chem. 2024, 20, 3026–3049, doi:10.3762/bjoc.20.252

• -CD synthesis is conducted by tosylation and a successive functional group transformation, and this tosylation often results in around 10% yield owing to the above reason. Because the mono-substituted α-CD is also useful in other stimuli-responsive material production [86], it’s easier synthesis was

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

• protecting group yielded the corresponding hydroxyalkynyl derivative 4. Subsequent Lindlar reduction resulted in the (Z)-alkene and a chemoselective tosylation of the primary alcohol led to the formation of tosylate 5. This intermediate underwent a stereospecific 4-exo cyclization upon exposure to iodine

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

• 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

• chromatography. Because 4.6 was obtained in better yields and in only 3 steps, the epimerization of 4.6 to 4.10 was also reported (Figure 4B). This epimerization is achieved in three-step sequence that starts with the double tosylation of 4.6 to produce 4.11. Then, the SN2 reaction with potassium acetate in DMSO

• 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

CO₂ complexation with cyclodextrins

• Cecilie Høgfeldt Jessen,
• Jesper Bendix,
• Theis Brock Nannestad,
• Heloisa Bordallo,
• Martin Jæger Pedersen,
• Christian Marcus Pedersen and
• Mikael Bols

Beilstein J. Org. Chem. 2023, 19, 1021–1027, doi:10.3762/bjoc.19.78

• compounds were made by tosylation of the corresponding partially benzylated cyclodextrins, hydrogenolysis and base treatment (see Supporting Information File 1 for experimental details). Compounds 5 and 6 have previously been made by direct tosylation of α-cyclodextrin which is a shorter route [17]. However

Aromatic C–H bond functionalization through organocatalyzed asymmetric intermolecular aza-Friedel–Crafts reaction: a recent update

• Anup Biswas

Beilstein J. Org. Chem. 2023, 19, 956–981, doi:10.3762/bjoc.19.72

• after recrystallization. Subsequent ozonolysis of the terminal alkene functionality with a follow-up reduction furnished primary alcohol 134 which was transformed into the azide 135. Reduction of the azide 135 was accompanied by debenzylation, was followed by tosylation of the primary amine and exchange

Continuous flow synthesis of 6-monoamino-6-monodeoxy-β-cyclodextrin

• János Máté Orosz,
• Dóra Ujj,
• Petr Kasal,
• Gábor Benkovics and
• Erika Bálint

Beilstein J. Org. Chem. 2023, 19, 294–302, doi:10.3762/bjoc.19.25

• and reduction. All reaction steps were studied separately and optimized under continuous flow conditions. After the optimization, the reaction steps were coupled in a semi-continuous flow system, since a solvent exchange had to be performed after the tosylation. However, the azidation and the

• efficient reaction used so far for the selective monofunctionalization of CDs [1]. Besides traditional synthetic methods, alternative techniques, such as ultrasound and microwave irradiation [21], as well as mechanosynthesis [22][23] for the functionalizations, such as tosylation or azidation of CDs have

• synthesis, but Ts-β-CD (2) can also be prepared by this route. However, before discussing these methods in more detail, some issues related to tosylation reagents should be considered. There are three tosylating agents utilized for the synthesis of Ts-β-CD, p-toluenesulfonyl chloride (TsCl) [14][28][29], (p

Synthesis, α-mannosidase inhibition studies and molecular modeling of 1,4-imino-ᴅ-lyxitols and their C-5-altered N-arylalkyl derivatives

• Martin Kalník,
• Sergej Šesták,
• Juraj Kóňa,
• Maroš Bella and
• Monika Poláková

Beilstein J. Org. Chem. 2023, 19, 282–293, doi:10.3762/bjoc.19.24

• in two steps from known ʟ-ribitol 1 [34] in good overall yield. Next, it was converted to the C-5 deoxygenated N-benzylpyrrolidine 6 via trityl ether cleavage, tosylation of the deprotected OH group, and reduction of the tosylate 5. Hydrogenolysis of the N-benzyl group in 6 followed by a removal of

Synthesis of the biologically important dideuterium-labelled adenosine triphosphate analogue ApppI(d₂)

• Petri A. Turhanen

Beilstein J. Org. Chem. 2022, 18, 1466–1470, doi:10.3762/bjoc.18.153

• -enoic acid (2) was then reduced to 3-methylbut-3-en-1,1-d2-1-ol (3) with lithium aluminium deuteride, followed by tosylation with tosyl chloride. Tosylated 3-methylbut-3-en-1,1-d2-1-ol 4 was then treated with ATP TBA salt in acetonitrile at 45 °C for 55 h to give the target product ApppI(d2) (Scheme 1

• , which was finally confirmed after the tosylation step and purification of compound 4. The signal at 68 ppm with clear carbon–deuterium coupling (1JCD = 22.9 Hz) in the 13C NMR spectrum was unambiguous proof of the doubly deuterated product 4. ApppI(d2) was isolated using two different amounts of TBA

Stepwise PEG synthesis featuring deprotection and coupling in one pot

• Logan Mikesell,
• Dhananjani N. A. M. Eriyagama,
• Yipeng Yin,
• Bao-Yuan Lu and
• Shiyue Fang

Beilstein J. Org. Chem. 2021, 17, 2976–2982, doi:10.3762/bjoc.17.207

• synthesis would be to react (PEG)4, which is commercially available and inexpensive, with styrene to give 6 [32], and tosylation of 6 to give the monomer (Scheme 3). However, the reported conditions for the synthesis of 6 without using an expensive catalyst gave low yields. We did not test the conditions

On the application of 3d metals for C–H activation toward bioactive compounds: The key step for the synthesis of silver bullets

• Renato L. Carvalho,
• Amanda S. de Miranda,
• Mateus P. Nunes,
• Roberto S. Gomes,
• Guilherme A. M. Jardim and
• Eufrânio N. da Silva Júnior

Beilstein J. Org. Chem. 2021, 17, 1849–1938, doi:10.3762/bjoc.17.126

• [158]. The synthesis started with a cyclopentene derivative, obtained after two steps from a diol via tosylation/displacement strategy with Me2CuLi·LiI. Then, after a Lewis acid-promoted cycloaddition, the alkylation of the α-carbon atom followed by regioselective Baeyer–Villiger oxidation provided the

Double-headed nucleosides: Synthesis and applications

• Vineet Verma,
• Jyotirmoy Maity,
• Vipin K. Maikhuri,
• Ritika Sharma,
• Himal K. Ganguly and
• Ashok K. Prasad

Beilstein J. Org. Chem. 2021, 17, 1392–1439, doi:10.3762/bjoc.17.98

• one-pot procedure in 55% yield. For this conversion, the carbonyl group at the 4-position of uracil was first activated by tosylation, which was followed by conversion to the amine upon reaction with ammonia and protection of the newly introduced amino group with benzoyl chloride to afford the double

• the nucleobases with propargyl bromide in the presence of K2CO3. Nucleoside 94 was synthesized from thymidine (93) which was first tritylated at the C-5′ primary hydroxy position followed by acetylation at the C-3′ secondary hydroxy group [61]. Next, detritylation and tosylation of the protected

Beyond ribose and phosphate: Selected nucleic acid modifications for structure–function investigations and therapeutic applications

• Christopher Liczner,
• Kieran Duke,
• Gabrielle Juneau,
• Martin Egli and
• Christopher J. Wilds

Beilstein J. Org. Chem. 2021, 17, 908–931, doi:10.3762/bjoc.17.76

• synthesis of LNA involves the tosylation of a 4'-C-hydroxymethyl derivative, followed by a base-induced ring closure to afford the 2'-O,4'-C-linked bicyclic nucleoside derivative (Scheme 6) [127][128]. Incorporation of LNA into a variety of oligonucleotides with varying lengths and sequences has shown

Synthesis of β-triazolylenones via metal-free desulfonylative alkylation of N-tosyl-1,2,3-triazoles

• Soumyaranjan Pati,
• Renata G. Almeida,
• Eufrânio N. da Silva Júnior and
• Irishi N. N. Namboothiri

Beilstein J. Org. Chem. 2021, 17, 762–770, doi:10.3762/bjoc.17.66

• can be explained by taking both hydrogen bonding and steric factors into consideration. In the solid as well as in the solution state, all the three above-mentioned 1,3-dicarbonyls exist in the enol form which are considerably stable and therefore undergo tosylation easily to form the corresponding O

All-carbon [3 + 2] cycloaddition in natural product synthesis

• Zhuo Wang and
• Junyang Liu

Beilstein J. Org. Chem. 2020, 16, 3015–3031, doi:10.3762/bjoc.16.251

• tetracyclic compound 56. Dihydroxylation of freshly prepared 56 with OsO4 and then selective tosylation afforded 57 in 39% yield over two steps. Exposure of 57 to DBU upon heating gave the elimination product 58, which was subjected to an oxidative rearrangement with PDC to give enone 59 in 68% yield. Copper

Optical detection of di- and triphosphate anions with mixed monolayer-protected gold nanoparticles containing zinc(II)–dipicolylamine complexes

• Lena Reinke,
• Julia Bartl,
• Marcus Koch and
• Stefan Kubik

Beilstein J. Org. Chem. 2020, 16, 2687–2700, doi:10.3762/bjoc.16.219

• synthesized in the racemic and the enantiomerically pure form. The racemate rac-1 was obtained in four steps from triethylene glycol monomethyl ether by tosylation, substitution of the tosyl by an azide group, and reduction to obtain the corresponding amine (Scheme 1). This amine was coupled to racemic lipoic

Syntheses of spliceostatins and thailanstatins: a review

• William A. Donaldson

Beilstein J. Org. Chem. 2020, 16, 1991–2006, doi:10.3762/bjoc.16.166

• ketals. The protection of the C-4 hydroxy group, hydrolysis of the acetonide, and selective tosylation of the 1° alcohol were prerequisites for the generation of the C-5–C-6 bond. To this end, the reaction of 82 with the ylide generated from trimethylsulfonium iodide gave the allylic alcohol 83. The

Fluorinated phenylalanines: synthesis and pharmaceutical applications

• Laila F. Awad and
• Mohammed Salah Ayoup

Beilstein J. Org. Chem. 2020, 16, 1022–1050, doi:10.3762/bjoc.16.91

• ). Alternatively, alcohol 91 was activated by tosylation to give 94 as a precursor for radiofluorination that was achieved to give 2-[18F]FELP ʟ-95 using [18F]-fluoride complexed with Kryptofix®/K+ followed by deprotection with HCl and purification. This product emerged as promising new PET tracer for brain tumor

Homo- and hetero-difunctionalized β-cyclodextrins: Short direct synthesis in gram scale and analysis of regiochemistry

• Gábor Benkovics,
• Mihály Bálint,
• Éva Fenyvesi,
• Erzsébet Varga,
• Szabolcs Béni,
• Konstantina Yannakopoulou and
• Milo Malanga

Beilstein J. Org. Chem. 2019, 15, 710–720, doi:10.3762/bjoc.15.66

• fact that in the large – kilogram – scale production of the key synthon 6-monotosyl-β-CD besides the desired product, over-tosylation occurs giving a mixture of regioisomers of ditosylated and tritosylated β-CDs. The ditosylated fraction represents a significant amount (10–20%) of the crude product

•  2), while the Cu(II)-mediated ditosylation in water/acetonitrile (ACN) mixture gave only two positional ditosyl-β-CD isomers in a ratio 6A,6C:6A,6D = 58:42, (reaction 2, Scheme 2). Tosylation in pyridine is known to be catalyzed by the oriented inclusion of the aromatic heterocycle into the cavity

• regioselectivity is observed. On the other hand, tosylation under aqueous basic conditions has a different reaction mechanism in which p-TsCl occupies the CD cavity prior to the reaction [23]. This orientation of the first tosyl group has a great impact on the substitution of the second tosyl moiety, which can

Enhanced single-isomer separation and pseudoenantiomer resolution of new primary rim heterobifunctionalized α-cyclodextrin derivatives

• Iveta Tichá,
• Gábor Benkovics,
• Milo Malanga and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2018, 14, 2829–2837, doi:10.3762/bjoc.14.261

• regioisomers on the primary rim of homobifunctionalized diazido-α-CDs by selective substitution on the primary rim. Specifically, three positional regioisomers 6A,6B-, 6A,6C-, and 6A,6D-diazido-α-CDs were prepared via different intermediates (using sulfonylation with capping agents, bromination and tosylation

• prepared all possible regioisomers of primary rim-disubstituted α-CD derivatives using the most common CD intermediates by commonly used derivatization (bromination, tosylation and capping). The three positional isomers (AB, AC, AD) were separated by ad hoc-developed HPLC methods, and the regioisomeric

• the preparation of 6A,6X-ditosyl-α-CD 6 under classical tosylation conditions with an excess of tosyl chloride (TsCl) in pyridine (reaction 5, Scheme 3). A previous study has shown [31] that tosyl groups exclusively attach to the primary rim of α-CD. Subsequently, the reaction mixture was converted

Synthesis of 1,4-imino-L-lyxitols modified at C-5 and their evaluation as inhibitors of GH38 α-mannosidases

• Maroš Bella,
• Sergej Šesták,
• Ján Moncoľ,
• Miroslav Koóš and
• Monika Poláková

Beilstein J. Org. Chem. 2018, 14, 2156–2162, doi:10.3762/bjoc.14.189

• protecting trityl group under acidic conditions followed by tosylation of the liberated hydroxy group with TsCl in the presence of DMAP as a base. Thus, required tosyl derivative 8 was obtained in 76% yield in two steps. It should be emphasized that tosylation in the presence of commonly used bases such as

Aminomethylation/hydrogenolysis as an alternative to direct methylation of metalated isoquinolines – a novel total synthesis of the alkaloid 7-hydroxy-6-methoxy-1-methylisoquinoline

• Benedikt C. Melzer,
• Jan G. Felber and
• Franz Bracher

Beilstein J. Org. Chem. 2018, 14, 130–134, doi:10.3762/bjoc.14.8

• starting aldehyde 2 was subjected to a reductive amination with aminoacetaldehyde dimethyl acetal and NaBH4, followed by N-tosylation and hydrochloric acid-mediated cyclization under concomitant N-detosylation and aromatization. Direct ring metalation of 3 with TMPMgCl∙LiCl was performed as described by us

Synthesis of ergostane-type brassinosteroids with modifications in ring A

• Vladimir N. Zhabinskii,
• Darya A. Osiyuk,
• Yuri V. Ermolovich,
• Natalia M. Chaschina,
• Tatsiana S. Dalidovich,
• Miroslav Strnad and
• Vladimir A. Khripach

Beilstein J. Org. Chem. 2017, 13, 2326–2331, doi:10.3762/bjoc.13.229

• stereospecific C(3) → C(2)-hydride shift/elimination process [30]. So, tosylation of the diol 14 occurred regioselectively at the equatorial C-2 hydroxy group to give monotosylate 30, which upon heating in pyridine, yielded compound 31 (Scheme 6). Its treatment with KOH in methanol led to 24-epi-3

Enzymatic separation of epimeric 4-C-hydroxymethylated furanosugars: Synthesis of bicyclic nucleosides

• Neha Rana,
• Manish Kumar,
• Vinod Khatri,
• Jyotirmoy Maity and
• Ashok K. Prasad

Beilstein J. Org. Chem. 2017, 13, 2078–2086, doi:10.3762/bjoc.13.205

• -toluenesulfonyloxymethyl-α-D-ribofuranose (5) and 5-O-acetyl-1,2-O-isopropylidene-4-C-p-toluenesulphonyloxymethyl-α-D-xylofuranose (10, Figure 2). The tosyl derivatives 5 and 10 of dihydroxyfuranosides 4a and 4b were obtained by their tosylation with TsCl-pyridine in 94 and 95% yields, respectively (Scheme 3 and Scheme 4

• , 100.6 MHz) δ 170.76, 113.56, 104.64, 86.87, 79.44, 72.84, 65.70, 62.23, 26.43, 26.20, 20.84; HR-ESI-TOF-MS m/z: [M + H]+ calcd. for [C11H19O7]+ 263.1125, found 263.1130. General procedure for the tosylation of monoacetylated sugar derivatives 4a and 4b: synthesis of compounds 5 and 10. Similar as