Refernces
10.1016/j.tet.2006.11.069
The research focuses on the synthesis of conformationally constrained tryptophan analogs, specifically 4-amino-3-oxo-tetrahydroazepino[3,4-b]indoles, which are designed to probe the bioactive conformation of peptides. The study employs SeO2 oxidation to obtain Boc-protected 20-formyl tryptophan, which is then subjected to reductive amination with various amines and amino acid esters using sodium cyanoborohydride. This is followed by ring closure to form the target compounds. The synthesized analogs are incorporated into the endomorphin-1 opioid peptide sequence to evaluate their bioactive conformation. The research utilizes molecular modeling, NMR spectroscopy, and receptor binding assays to analyze the conformational properties and biological activities of the synthesized compounds. The experiments involve the use of various analytical techniques such as RP-HPLC, TLC, MS, and NMR to monitor the progress of reactions, characterize the compounds, and assess their binding affinities to opioid receptors.
10.1007/s10600-007-0065-6
The research focuses on the synthesis of N-methyl urocanates of hydroxy derivatives of isocembrol, which are proposed biomimetics of taxol and exhibit cytotoxic activity similar to eleutherobin and sarcodictyins. The experiments involved stereospecific hydroxylation of isocembrol to prepare alcohols, which were then esterified into N-methylurocanates. Key reactants included isocembrol, t-butylhydroperoxide (TBHP), VO(acac)2, LiAlH4, (i-Bu)2AlH, SeO2, and N-methylurocanic acid, among others. The analyses used to characterize the products and intermediates were primarily nuclear magnetic resonance (NMR) spectroscopy, including both proton (PMR) and carbon (13C NMR) variants, as well as thin-layer chromatography (TLC), optical rotation measurements, and melting point determinations. These techniques were crucial in establishing the regio- and stereochemistry of the synthesized compounds.
10.1021/jo00299a031
The research aimed to synthesize pentaleno[2,1-b:5,4-b']diindoles, which are complex organic compounds, using a combination of the Weiss reaction and the Fischer indole cyclization. The purpose was to prepare hexahydro-5,11-dihydropentaleno[2,1-b:5,4-b']diindoles and convert them into various 6,12-disubstituted derivatives. Despite numerous attempts, the researchers were unable to successfully convert these intermediates into bis(indo1o-substituted)pentalenes 5 or 6, as all attempts resulted in decomposition or ring scission products. The chemicals used in this process included phenylhydrazine, hydrochloric acid, selenium dioxide, phenylselenol, zinc iodide, and various solvents and reagents for chromatography and spectroscopic analysis. The conclusions drawn from the research were that while the diindole perhydropentalenes could be synthesized, the stabilization provided by the indole units in the targeted pentalenes was insufficient to prevent decomposition, suggesting that the benzene rings in dibenzopentalenes offer more effective stabilization than the indole units.
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T:Toxic;
