نتایج جستجو برای: 3 diketones
تعداد نتایج: 1811794 فیلتر نتایج به سال:
We report herein a point-to-axial chirality transfer reaction of optical dihydrophenanthrene-9,10-diols for the synthesis axially chiral diketones. Two sets conditions, namely basic tBuOK/air atmosphere and an acidic NaClO/n-Bu4NHSO4, were developed to oxidatively cleave C-C bond, resulting in formation biaryl Finally, brief synthetic applications obtained aryl diketones demonstrated.
The perchlorate salt of the dicationic bipy-ruthenium complex cis-[Ru(6,6'-Cl2bipy)2(H2O)2]2+ effectively catalyzes addition of beta-diketones to secondary alcohols and styrenes to yield the alpha-alkylated beta-diketones. In a catalytic addition reaction of acetylacetone to 1-phenylethanol, the kappa2-acetylacetonate complex [Ru(6,6'-Cl2bipy)2(kappa2-acac)]ClO4 was isolated after the catalysis...
Photochemical processes of 4-tert-butyl-4'-methoxydibenzoylmethane (Avobenzone, AB), 4-phenylbenzoylbenzoyl-, 4-phenylbenzoyl-2'-furanyl- and 4-phenylbenzoyl-2'-thenoylmethanes (PB@Ph, PB@F and PB@T, respectively) substituted with Br and Cl at the C2 position were studied by stationary and laser flash photolyses in solution. The absorption spectral features showed that the molecular structures ...
Arylalkynes can be converted into α-diketones with the use of a copper catalyst, and also be transformed into vinyl acetates under metal-free conditions, both in the presence of PhI(OAc)2 as an oxidant at room temperature. A series of substituted α-diketones were prepared in moderate to good yields. A variety of vinyl halides could be regio- and stereo-selectively synthesized under mild conditi...
The kinetic method is used to corroborate the description of ground state ionized alpha-diketones as loosely electron-bonded acylium ion dimers: R(1)-C=O(+)---e(-)---(+)O=C-R(2). The abundance ratio of both the acylium ion fragments R(1)CO(+) and R(2)CO(+) (summed to those of their respective secondary fragments) formed upon low energy (5 eV) collision-induced dissociation of several ionized al...
The beta0diketone derivatives of nitroimidazole were synthesized from the reaction of magnesium salt of beta-ketoaccids 3 with imidazolide 4. The raction of beta-diketones with hydroxylamine hydrochloride afforded either the isoxazoles or the 5-hydroxyl-2-isoxazolines.
We have discovered new characteristics of D-erythrulose reductase, namely, that it can catalyze reduction of not only D-erythrulose but also such diketones as diacetyl. These substrates have a common structure with two neighboring carbonyls possibly in s-cis plane structure, showing that the enzyme may rigorously distinguish between substrates and other compounds. D-Erythrulose reductase was pr...
Synthesis and Spectral Characterization of Novel 2, 3-Disubstituted Quinazolin-4(3H) one Derivatives
New series of 2,3-disubstituted quinazolin-4(3H)one were synthesized via the reaction of the readily obtainable 2-thioxo-3-phenyl-quinazolin-4(3H)one 1 with ethyl chloroacetate followed by hydrazinolysis to afford the hydrazide 3 which allowed to react with different electrophilic reagents such as carbon disulphide, phenyl isothiocyanate, β-diketones, anhydrides, acrylonitrile, ethyl cinnamate,...
The paper updates Isler's monograph of 1971 regarding the structures of naturally occurring carotenoids, their chemical reactions and their stereochemistry. Around ninety new structures are reported, including the new series of C30-carotenoids, enolized /3-diketones and several carotenoids with 2-hydroxy 3-rings. Progress in stereochemistry resulting in the configurational assignment of eleven ...
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