The preparation and properties of 1,1-difluorocyclopropane derivatives

• Kymbat S. Adekenova,
• Peter B. Wyatt and
• Sergazy M. Adekenov

Beilstein J. Org. Chem. 2021, 17, 245–272, doi:10.3762/bjoc.17.25

Glycosylation reactions mediated by hypervalent iodine: application to the synthesis of nucleosides and carbohydrates

• Yuichi Yoshimura,
• Hideaki Wakamatsu,
• Yoshihiro Natori,
• Yukako Saito and
• Noriaki Minakawa

Beilstein J. Org. Chem. 2018, 14, 1595–1618, doi:10.3762/bjoc.14.137

• well. The extension of hypervalent iodine-mediated glycosylation allowed us to couple a nucleobase with cyclic allylsilanes and glycal derivatives to yield carbocyclic nucleosides and 2’,3’-unsaturated nucleosides, respectively. In addition, the combination of hypervalent iodine and Lewis acid could be

• reaction coupled with oxidation. The concept of the oxidative glycosylation reaction was successfully applied to the synthesis of other nucleoside derivatives, including 4’-selenonucleosides and carbocyclic nucleosides. The hypervalent iodine-mediated glycosylation has also been used for oligosaccharide

• desired guanosine derivative 82 [60] (Scheme 11). As in the case of 4’-thionucleosides, the use of hypervalent iodine greatly improved the glycosylation reaction with 4-seleosugars by skipping the preparation of unstable selenoxide derivatives. Synthesis of carbocyclic nucleosides As described above, in

Recent advances in synthetic approaches for medicinal chemistry of C-nucleosides

• Kartik Temburnikar and
• Katherine L. Seley-Radtke

Beilstein J. Org. Chem. 2018, 14, 772–785, doi:10.3762/bjoc.14.65

• . The O–C–N bond between nucleobase and sugar defines the glycosidic bond. Replacement of nucleobase nitrogen by carbon results in C-nucleosides. A carbon (CH2) replacing the sugar oxygen results in carbocyclic nucleosides. When both the heteroatoms in the glycosidic bond are replaced by carbon, the

Acid-catalyzed ring-opening reactions of a cyclopropanated 3-aza-2-oxabicyclo[2.2.1]hept-5-ene with alcohols

• Katrina Tait,
• Alysia Horvath,
• Nicolas Blanchard and
• William Tam

Beilstein J. Org. Chem. 2017, 13, 2888–2894, doi:10.3762/bjoc.13.281

• the synthesis of 2’,3’-methano carbocyclic nucleosides via compound 24 (Scheme 5) [17]. Carbocyclic nucleosides are important synthetic targets because of their use as antiviral and antitumor agents [17]. Replacing the oxygen unit in the parent furanose ring with a methylene unit helps to stabilize

Revaluation of biomass-derived furfuryl alcohol derivatives for the synthesis of carbocyclic nucleoside phosphonate analogues

• Bemba Sidi Mohamed,
• Christian Périgaud and
• Christophe Mathé

Beilstein J. Org. Chem. 2017, 13, 251–256, doi:10.3762/bjoc.13.28

• -Boc-adenine or 2-amino-6-chloropurine in the presence of diisopropyl azodicarboxylate (DIAD) and PPh3, provided the N9 carbocyclic nucleosides (+/−)-8 and (+/−)-9 as racemic mixtures. No concomitant formation of the N7 regioisomer was observed. The removal of Boc and acetyl groups from (+/−)-8

Synthesis of novel N-cyclopentenyl-lactams using the Aubé reaction

• Madhuri V. Shinde,
• Rohini S. Ople,
• Ekta Sangtani,
• Rajesh Gonnade and
• D. Srinivasa Reddy

Beilstein J. Org. Chem. 2015, 11, 1060–1067, doi:10.3762/bjoc.11.119

• , India 10.3762/bjoc.11.119 Abstract A novel and convenient method utilizing the Aubé reaction to access a new class of compounds that are similar to carbocyclic nucleosides is reported. The azido alcohol derived from Vince lactam undergoes the Aubé reaction with various cyclic ketones to give

• : Aubé reaction; biological activity; carbocyclic nucleosides; cyclopentenylated lactams; cyclopentylated lactams; Introduction One popular method for the synthesis of N-substituted lactams is the Aubé reaction [1][2][3][4]. Over the last few decades, this reaction has gained popularity and resulted in

• conjugates starting from an azido-alcohol embedded in sugar derivatives and cyclic ketones [16]. In continuation of this work (and also to expand the potential of this chemistry), a new class of compounds were prepared. These cyclopentenoid–lactams, which look like carbocyclic nucleosides, were prepared

Understanding the mechanism of Pd-catalyzed allylic substitution of the cyclic difluorinated carbonates

• Jun Xu,
• Xiao-Long Qiu and
• Feng-Ling Qing

Beilstein J. Org. Chem. 2008, 4, No. 18, doi:10.3762/bjoc.4.18

• , Shanghai 201620, China 10.3762/bjoc.4.18 Abstract We present a mechanistic investigation of Pd-catalyzed allylic substitution of cyclic gem-difluorinated carbonates 1 and 4, previously employed in the synthesis of 3',3'-difluoro-2'-hydroxymethyl-4',5'-unsaturated carbocyclic nucleosides in 17 steps. The

• substitution features a reversal of regioselectivity caused by fluorine. Background Carbocyclic nucleosides (CNAs), in which the furanose oxygen atoms of the 4'-oxonucleosides are substituted by CH2, have received considerable attention because they exhibit greater metabolic stability toward nucleoside

• phosphorylases and higher lipophilicity, two properties that are potentially beneficial in terms of increased in vivo half life, oral efficiency and cell wall penetration [1][2]. Based on CNA skeletons, 1,2-disubstituted carbocyclic nucleosides (OTCs) recently attracted more and more attention [3][4][5][6][7][8