The Bischler–Napieralski reaction is an intramolecular electrophilic aromatic substitution reaction that allows for the cyclization of β-arylethylamides or β-arylethylcarbamates. It was first discovered in 1893 by August Bischler and Bernard Napieralski, in affiliation with Basel Chemical Works and the University of Zurich. The reaction is most notably used in the synthesis of dihydroisoquinolines, which can be subsequently oxidized to isoquinolines.
Tetrahedron is a weekly peer-reviewed scientific journal covering the field of organic chemistry. According to the Journal Citation Reports, Tetrahedron has a 2020 impact factor of 2.1. Tetrahedron and Elsevier, its publisher, support an annual symposium. In 2010, complaints were raised over its high subscription cost.
The Wurtz–Fittig reaction is the chemical reaction of an aryl halide, alkyl halides, and sodium metal to give substituted aromatic compounds. Following the work of Charles Adolphe Wurtz on the sodium-induced coupling of alkyl halides, Wilhelm Rudolph Fittig extended the approach to the coupling of an alkyl halide with an aryl halide. This modification of the Wurtz reaction is considered a separate process and is named for both scientists.
γ-Carotene (gamma-carotene) is a carotenoid, and is a biosynthetic intermediate for cyclized carotenoid synthesis in plants. It is formed from cyclization of lycopene by lycopene cyclase epsilon. Along with several other carotenoids, γ-carotene is a vitamer of vitamin A in herbivores and omnivores. Carotenoids with a cyclized, beta-ionone ring can be converted to vitamin A, also known as retinol, by the enzyme beta-carotene 15,15'-dioxygenase; however, the bioconversion of γ-carotene to retinol has not been well-characterized. γ-Carotene has tentatively been identified as a biomarker for green and purple sulfur bacteria in a sample from the 1.640 ± 0.003-Gyr-old Barney Creek Formation in Northern Australia which comprises marine sediments. Tentative discovery of γ-carotene in marine sediments implies a past euxinic environment, where water columns were anoxic and sulfidic. This is significant for reconstructing past oceanic conditions, but so far γ-carotene has only been potentially identified in the one measured sample.
The Achmatowicz reaction, also known as the Achmatowicz rearrangement, is an organic synthesis in which a furan is converted to a dihydropyran. In the original publication by the Polish Chemist Osman Achmatowicz Jr. in 1971 furfuryl alcohol is reacted with bromine in methanol to 2,5-dimethoxy-2,5-dihydrofuran which rearranges to the dihydropyran with dilute sulfuric acid. Additional reaction steps, alcohol protection with methyl orthoformate and boron trifluoride) and then ketone reduction with sodium borohydride produce an intermediate from which many monosaccharides can be synthesised.
The Abramov reaction is the related conversions of trialkyl to α-hydroxy phosphonates by the addition to carbonyl compounds. In terms of mechanism, the reaction involves attack of the nucleophilic phosphorus atom on the carbonyl carbon. It was named after the Russian chemist Vasilii Semenovich Abramov (1904–1968) in 1957.
Desulfonylation reactions are chemical reactions leading to the removal of a sulfonyl group from organic compounds. As the sulfonyl functional group is electron-withdrawing, methods for cleaving the sulfur–carbon bonds of sulfones are typically reductive in nature. Olefination or replacement with hydrogen may be accomplished using reductive desulfonylation methods.
Gummadiol is a lignan hemiacetal. It can be isolated from the heartwood of Gmelina arborea.
Fétizon oxidation is the oxidation of primary and secondary alcohols utilizing the compound silver(I) carbonate absorbed onto the surface of celite also known as Fétizon's reagent first employed by Marcel Fétizon in 1968. It is a mild reagent, suitable for both acid and base sensitive compounds. Its great reactivity with lactols makes the Fétizon oxidation a useful method to obtain lactones from a diol. The reaction is inhibited significantly by polar groups within the reaction system as well as steric hindrance of the α-hydrogen of the alcohol.
Chaetoglobosin A is a fungal isolate with anticancer activity in vitro. Derivatives of the compound include MBJ-0038, MBJ-0039, and MBJ-0040.
Hericenones is a class of benzaldehydes that are isolates of the fruiting body of Hericium erinaceum that promote nerve growth factor synthesis in vitro.
Gmelanone is a lignan found in the heartwood of Gmelina arborea. Arboreol can be transformed by acid catalysis into gmelanone.
Vanillylamine is a chemical compound that is an intermediate in the biosynthesis of capsaicin. Vanillylamine is produced from vanillin by the enzyme vanillin aminotransferase. It is then converted with 8-methyl-6-nonenoic acid into capsaicin by the enzyme capsaicin synthase.
Tremetone is a constituent of the toxic compound tremetol, found in snakeroot, that causes milk sickness in humans and trembles in livestock. Tremetone is the main constituent of at least 11 chemically related substances in tremetol. Tremetone is toxic to fish, but not to chicken, and is therefore not the major toxic compound in tremetol. Tremetol can be found in a number of different species of the family Asteraceae, including snakeroot and rayless goldenrod.
SCH-202,596 is a natural product which is a metabolite derived from an Aspergillus fungus. It acts as a selective non-peptide antagonist for the receptor GAL-1, which is usually activated by the neuropeptide galanin. SCH-202,596 is used for scientific research into this still little characterised receptor subtype.
Penicillium brefeldianum is an anamorph fungus species of the genus of Penicillium which produces Brefeldin A a fungal metabolite.
17α-Methyl-19-norprogesterone, also known as 17α-methyl-19-norpregn-4-ene-3,20-dione, is a progestin which was never marketed. It is a derivative of progesterone, and is the combined derivative of 17α-methylprogesterone and 19-norprogesterone. The drug is the parent compound of a subgroup of the 19-norprogesterone group of progestins, which includes demegestone, promegestone, and trimegestone.
In organic chemistry, the Davis oxidation or Davis' oxaziridine oxidation refers to oxidations involving the use of the Davis reagent or other similar oxaziridine reagents. This reaction mainly refers to the generation of α-hydroxy carbonyl compounds (acyloins) from ketones or esters. The reaction is carried out in a basic environment to generate the corresponding enolate from the ketone or ester. This reaction has been shown to work for amides.
Collybolide is a secondary metabolite of the Rhodocollybia maculata mushroom, a basidiomycete fungus that grows on rotting conifer wood. It was previously believed to be a potent and selective kappa-opioid receptor agonist. However, a total synthesis and independent biological assay determined that collybolide neither excites nor suppresses kappa-opioid receptor signaling. Collybolide is unlikely to be psychoactive, although it has been shown to inhibit L-type calcium channels in isolated rat aorta.
Jiro Tsuji was a Japanese chemist, notable for his discovery of organometallic reactions, including the Tsuji-Trost reaction, the Tsuji-Wilkinson decarbonylation, and the Tsuji-Wacker reaction.
