نتایج جستجو برای: formation of ketone

تعداد نتایج: 21205055  

Journal: :Tetrahedron 2021

Wacker-type reactions of terminal alkenes mainly lead to methyl ketones rather than aldehydes. The selective formation aldehydes usually requires containing a suitable coordinating fragment. A few procedures however provide fair high aldehyde/methyl ketone ratios in the absence directing group. This review, which is focused on aldehydes, summarizes methods reported since 2007 and, with personal...

Journal: :IOP conference series 2023

Abstract The synthesis of ketones from C18:1 fatty acid using the decarboxylation method has been carried out to increase added value oil palm derivative products. One products is Crude Palm Oil, which can be converted into acids through triglyceride hydrolysis process. Currently, are most potential environmentally friendly raw material in Indonesia. This research aims synthesize under differen...

Journal: :journal of heat and mass transfer research 0
akanksha swarnkar national institute of technology, raipur. amit keshav national institute of technology anupam bala soni national institute of technology

the feasibility of extractive reaction of methacrylic acid from aqueous solution using a quaternary amine, tri–octyl methyl ammonium chloride (tomac) as an extractant, was studied. the diluents chosen in the present work belong to different chemical classes, n–butyl acetate, carbon tetrachloride, isoamyl alcohol, methyl isobutyl ketone, and toluene. the effect of initial acid concentration in t...

2014
Julio Zukerman-Schpector Stella H. Maganhi Paulo J. S. Moran Bruno R. S. de Paula Paulo R. Nucci Edward R. T. Tiekink

In the title compound, C17H15NO4, the conformation about the C=C double bond [1.348 (2) Å] is E with the ketone group almost co-planar [C-C-C-C torsion angle = 7.2 (2)°] but the phenyl group twisted away [C-C-C-C = 160.93 (17)°]. The terminal aromatic rings are almost perpendicular to each other [dihedral angle = 81.61 (9)°] giving the mol-ecule an overall U-shape. The crystal packing feature b...

Journal: :The Journal of biological chemistry 1986
J Rosing R F Zwaal G Tans

The conversion of prothrombin into thrombin by Factor Xa requires the cleavage of two peptide bonds in prothrombin. Dependent on the order of cleavage, prethrombin 2 or meizothrombin occurs as intermediate. Since prethrombin 2 has as yet been the only observed intermediate, prothrombin activation is generally considered to proceed via prethrombin 2. In this paper we present new methods that all...

1999
O. Shestakov S. Jagiella J. Theloke H. G. Libuda F. Zabel

Alkoxy (R1C(R2)(R3)O•) and Carbonyl (RC(•)O) radicals are important intermediates in the degradation chain of hydrocarbons. Both classes of radicals are subject to competing reaction chan-nels leading to different products which exhibit different ozone formation potentials: Alkoxy radicals (1) Reaction with O2 (kO2, => aldehyde/ketone + HO2); (2) thermal decomposition (kdis, => aldehyde/ketone ...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 1998
W E Hull A Berkessel W Plaga

Approximately 2 micromol of a novel prokaryotic pheromone, involved in starvation-induced aggregation and formation of fruiting bodies by the myxobacterium Stigmatella aurantiaca, were isolated by a large-scale elution procedure. The pheromone was purified by HPLC, and high-resolution MS, IR, 1H-NMR, and 13C-NMR were used to identify the active substance as the hydroxy ketone 2,5, 8-trimethyl-8...

2012
Abdullah M. Asiri Hassan M. Faidallah Khalid A. Alamry Seik Weng Ng Edward R. T. Tiekink

In the title compound, C(15)H(12)OS, the cyclo-hexene ring has a twisted boat conformation with the C atom between the ketone and methyl-ene atom and this methyl-ene C atom lying 0.280 (3) and 0.760 (3) Å, respectively, from the plane through the remaining four atoms (r.m.s. deviation = 0.004 Å). The dihedral angle between the benzene and thio-phene rings [21.64 (9)°] indicates an overall twist...

Journal: :Journal of the American Chemical Society 2004
Bohumil Dolenský Jirí Kroulík Vladimír Král Jonathan L Sessler Hana Dvoráková Petr Bour Markéta Bernátková Christophe Bucher Vincent Lynch

A new, stepwise synthesis of calix[4]phyrins is described. It relies on the condensation of a ketone with pyrrole to form a dipyrromethane containing a quaternary carbon center that is subsequently condensed with an aromatic aldehyde. This methodology, in contrast to the previous rational approach described by this group (involving formation of a trisubstituted dipyrromethane via the condensati...

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