Advances in mercury(II)-salt-mediated cyclization reactions of unsaturated bonds

• Sumana Mandal,
• Raju D. Chaudhari and
• Goutam Biswas

Beilstein J. Org. Chem. 2021, 17, 2348–2376, doi:10.3762/bjoc.17.153

• cyclization reactions, there were examples where a Hg(II)-salt-mediated cyclization had been successfully employed as one of the important steps during the total synthesis of natural products. In 1998, a highly enantioselective total synthesis of (+)-furanomycin (190) was achieved through Hg(TFA)2-promoted

N-(1-Phenylethyl)aziridine-2-carboxylate esters in the synthesis of biologically relevant compounds

• Iwona E. Głowacka,
• Aleksandra Trocha,
• Andrzej E. Wróblewski and
• Dorota G. Piotrowska

Beilstein J. Org. Chem. 2019, 15, 1722–1757, doi:10.3762/bjoc.15.168

• presence of acetic anhydride produced a crude acetamido ester (R)-132 which was transformed into the final N-benzyl amide (R)-130 with of 99.9% ee after crystallization. ʟ-(+)-Furanomycin (Scheme 35) is a natural nonproteinogenic amino acid which showed pronounced antibacterial activity. From several

• )-135 instead of the allyl residue opened the way to synthesis of ʟ-(+)-furanomycin and its 5'-epimer. MeBmt (2S,3R,4R,6E)-139 is a nonproteinogenic amino acid found as a constituent of the naturally occurring cyclic peptide cyclosporine currently in medical use as immunosuppressant [89]. Syntheses of

New tricks of well-known aminoazoles in isocyanide-based multicomponent reactions and antibacterial activity of the compounds synthesized

• Maryna V. Murlykina,
• Maryna N. Kornet,
• Sergey M. Desenko,
• Svetlana V. Shishkina,
• Oleg V. Shishkin,
• Aleksander A. Brazhko,
• Vladimir I. Musatov,
• Erik V. Van der Eycken and
• Valentin A. Chebanov

Beilstein J. Org. Chem. 2017, 13, 1050–1063, doi:10.3762/bjoc.13.104

• , anti-inflammatory [28][43], antiviral [39][44], antidiabetic [45] effects and cancer cell growth-inhibitory features should be mentioned [29][46][47][48]. Ugi-4CR has been applied in the synthesis of natural products, as bicyclomycin, furanomycin, penicillin etc. [53]. The high combinatorial potential

Garner’s aldehyde as a versatile intermediate in the synthesis of enantiopure natural products

• Mikko Passiniemi and
• Ari M.P. Koskinen

Beilstein J. Org. Chem. 2013, 9, 2641–2659, doi:10.3762/bjoc.9.300

• six-membered rings. Five-membered dihydrofuran rings lead to the synthesis of furanomycin D [35][36], norfuranomycin E [37], and the polyoxin family F [38]. The six-membered tetrahydropyridine G synthesized via this route can be used as an intermediate in the synthesis of iminosugars, e.g., of the

An approach towards azafuranomycin analogs by gold-catalyzed cycloisomerization of allenes: synthesis of (αS,2R)-(2,5-dihydro-1H-pyrrol-2-yl)glycine

• Jörg Erdsack and
• Norbert Krause

Beilstein J. Org. Chem. 2013, 9, 1936–1942, doi:10.3762/bjoc.9.229

• ; amino acids; cuprates; furanomycin; gold catalysis; Introduction In 1967, Katagiri et al. reported the isolation of a novel antibiotic from the culture broth of the fungus Streptomyces threomyceticus [1]. The compound acts as a competitive antagonist for isoleucine in vitro and hampers the growth of

• several microorganisms, including the E. coli, S. aureus and M. tuberculosis. (+)-Furanomycin (1a, Figure 1, X = O) was identified as a non-proteinogenic amino acid bearing a characteristic 2,5-dihydrofuran ring. The correct (αS,2R,5S)-stereochemistry was established in 1980 by the first total synthesis

• by Joullié and co-workers [2] and the X-ray analysis of the N-acetyl derivative of the natural product by Shiro et al. [3]. (+)-Furanomycin belongs to the smallest natural antibiotics [4]. Therefore, the compound found considerable interest in synthetic chemistry. Until today, five total syntheses