Prins cyclization-mediated stereoselective synthesis of tetrahydropyrans and dihydropyrans: an inspection of twenty years

• Asha Budakoti,
• Pradip Kumar Mondal,
• Prachi Verma and
• Jagadish Khamrai

Beilstein J. Org. Chem. 2021, 17, 932–963, doi:10.3762/bjoc.17.77

• products [1][2][3][4][5][6][7][8]. Prins and related cyclization reactions [9][10], hetero-Diels–Alder cyclization [11], cyclization onto epoxides [12], Petasis–Ferrier rearrangement [13], intramolecular oxa-Michael reactions [14], cyclization through oxidative C–H bond functionalization [15], ring-closing

Robust perfluorophenylboronic acid-catalyzed stereoselective synthesis of 2,3-unsaturated O-, C-, N- and S-linked glycosides

• Madhu Babu Tatina,
• Xia Mengxin,
• Rao Peilin and
• Zaher M. A. Judeh

Beilstein J. Org. Chem. 2019, 15, 1275–1280, doi:10.3762/bjoc.15.125

• developed for the synthesis of 2,3-unsaturated C-, O-, N- and S-linked glycosides (enosides) using 20 mol % perflurophenylboronic acid catalyst via Ferrier rearrangement. Using this protocol, D-glucals and L-rhamnals reacted with various C-, O-, N- and S-nucleophiles to give a wide range of glycosides in up

• to 98% yields with mainly α-anomeric selectivity. The perflurophenylboronic acid successfully catalyzed a wide range of substrates (both glucals and nucleophiles) under very mild reaction conditions. Keywords: C-; O-; N- and S-linked glycosides; enosides; Ferrier-rearrangement; organocatalyst

• ]. The Ferrier rearrangement is one of the most useful processes to synthesize pseudo-glycosides in a direct and stereoselective fashion. Several classes of catalysts have been successfully applied in the Ferrier rearrangement including Brønsted acids [7][8][9][10][11][12][13], Lewis acids [14][15][16

Anomeric modification of carbohydrates using the Mitsunobu reaction

• Julia Hain,
• Patrick Rollin,
• Werner Klaffke and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2018, 14, 1619–1636, doi:10.3762/bjoc.14.138

• also employed with glycals like 86 and 87 reacting with p-methoxyphenol as an alternative to the Ferrier rearrangement in the synthesis of 2-C-methylene glycosides and other rearrangement products 88–92, some of which cannot be obtained in a classical Ferrier reaction (Scheme 16) [69][70][71][72]. The

AuBr₃-catalyzed azidation of per-O-acetylated and per-O-benzoylated sugars

• Jayashree Rajput,
• Srinivas Hotha and
• Madhuri Vangala

Beilstein J. Org. Chem. 2018, 14, 682–687, doi:10.3762/bjoc.14.56

• -glycosides are also accessible by AuCl3/phenylacetylene-promoted Ferrier rearrangement of glycals [17], thus, demonstrating the efficient catalysis by alkynophilic and carbophilic Au complexes. Although the alkynophilicity and carbophilicity of Au complexes are well explored, very little is known about the

Intramolecular glycosylation

• Xiao G. Jia and
• Alexei V. Demchenko

Beilstein J. Org. Chem. 2017, 13, 2028–2048, doi:10.3762/bjoc.13.201

• secondary sugar acceptors worked well providing disaccharides with high β-selectivity and good yields. Overall, compounds 93 and 96, obtained as a result of this interesting reaction, represent products of the Ferrier rearrangement, 2,3-dehydro derivatives. Leaving group-based methods This overview

Silyl-protective groups influencing the reactivity and selectivity in glycosylations

• Mikael Bols and
• Christian Marcus Pedersen

Beilstein J. Org. Chem. 2017, 13, 93–105, doi:10.3762/bjoc.13.12

• alcohols such as 73, catalyzed by p-TsOH, gave exclusively α-glucoside 74 (Scheme 15). When the same glycosylation was performed with the fully benzylated or TBS-protected glucal the reaction gave a lower yield and was accompanied by some formation of the β-anomer and some Ferrier rearrangement product

TMSBr-mediated solvent- and work-up-free synthesis of α-2-deoxyglycosides from glycals

• Mei-Yuan Hsu,
• Yi-Pei Liu,
• Sarah Lam,
• Su-Ching Lin and
• Cheng-Chung Wang

Beilstein J. Org. Chem. 2016, 12, 1758–1764, doi:10.3762/bjoc.12.164

• ][57][58][59][60][61][62][63]. However, based on the hard and soft (Lewis) acids and bases (HSAB) theory, hard acids would coordinate to the harder O3 in glycals in preference to the softer alkene to initiate an undesired Ferrier rearrangement, leading to the formation of a considerable amount of 2,3

A general metal-free approach for the stereoselective synthesis of C-glycals from unactivated alkynes

• Shekaraiah Devari,
• Manjeet Kumar,
• Ramesh Deshidi,
• Masood Rizvi and
• Bhahwal Ali Shah

Beilstein J. Org. Chem. 2014, 10, 2649–2653, doi:10.3762/bjoc.10.277

• terminal alkynes are required. Further studies are underway to broaden the scope of the present reaction. C-alkynylation of glycals. Substrate scope of the reaction process under optimized reaction conditions. Plausible mechanism of the Ferrier rearrangement. Alkynylation reaction of 3,4,6-tri-O-acetyl-D

Efficient carbon-Ferrier rearrangement on glycals mediated by ceric ammonium nitrate: Application to the synthesis of 2-deoxy-2-amino-C-glycoside

• Alafia A. Ansari,
• Y. Suman Reddy and
• Yashwant D. Vankar

Beilstein J. Org. Chem. 2014, 10, 300–306, doi:10.3762/bjoc.10.27

• Alafia A. Ansari Y. Suman Reddy Yashwant D. Vankar Department of Chemistry, Indian Institute of Technology Kanpur 208 016, India 10.3762/bjoc.10.27 Abstract A carbon-Ferrier rearrangement on glycals has been performed by using ceric ammonium nitrate to obtain products in moderate to good yields

• -glycosides; carbon-Ferrier rearrangement; ceric ammonium nitrate; 2-deoxy-2-aminoglycosides; Overman rearrangement; Introduction The growing significance of C-glycosides can be attributed to their potential use as inhibitors of carbohydrate-processing enzymes [1][2][3], their extraordinary stability

• synthesis of C-glycosides [12][13][14]. Among these, the Ferrier rearrangement [15] of glycals with protic acids [5][16][17] or Lewis acids [18][19][20][21][22] and carbon nucleophiles such as allylsilanes [23], silylacetylenes [24], silyl enol ethers [25], olefins [26], and organozinc reagents [27] has