502-72-7Relevant articles and documents
Synthesis of Cyclopentadecanone by Ring Contraction of Cyclohexadecanone
Kato, Tetsuya,Kondo, Hisao,Miyake, Akihisa
, p. 823 - 824 (1980)
Cyclopentadecanone has been synthesized from cyclohexadecanone. 2,2,15-Tribromocyclohexadecanone, upon treatment with sodium methoxide, underwant the Favorskii rearrangement via methyl 2-bromo-1-cyclopentadecene-1-carboxylate to produce a mixture of methyl 2-methoxy-1-cyclopentadecene-1-carboxylate, methyl 2-methoxy-2-cyclopentadecene-1-carboxylate, and methyl 2,2-dimethoxycyclopentadecane-1-carboxylate which was converted into cyclopentadecanone.
Photochemical Transformations with Iodine Azide after Release from an Ion-Exchange Resin
Dr?ger, Gerald,K?sel, Teresa,Kirschning, Andreas,Schulz, G?ran
supporting information, p. 12376 - 12380 (2020/05/08)
This report discloses the photochemical homolytic cleavage of iodine azide after its formation following release from polymer-bound bisazido iodate(I) anions. A series of radical reactions are reported including the 1,2-functionlization of alkenes and the unprecedented chemoselective oxidation of secondary alcohols in the presence of primary alcohols.
Cyclopentadecanon preparation method
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, (2018/03/26)
The invention discloses a cyclopentadecanon preparation method. Specifically, the method comprises the following steps: (a) in an inert solvent, reacting formula IV compound with diazomethane to formformula III compound; (b) in the inert solvent, reacting the formula III compound with the diazomethane to form formula II compound; (c) in the inert solvent, reacting the formula II compound with thediazomethane to form formula I compound. The method disclosed by the invention has the characteristics of ability in accurately controlling pressure and material feeding, ability in greatly improvingreaction speed, stable reaction yield, high product purity and low technological cost; thus, the method has a wide application prospect.
Cyclopentadecanone preparation method
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, (2018/04/28)
The invention provides a cyclopentadecanone preparation method. The method includes that cyclododecene and acryloyl chloride are subjected to reaction to obtain a ketene intermediate shown as a formula (II), the intermediate and a sulfuryl hydrazine compound are subjected to reaction to obtain a hydrazone intermediate shown as a formula (III), and the hydrazone intermediate is subjected to ring opening and hydrogenation to obtain a cyclopentadecanone product shown as a formula (V). Compared with a traditional cyclopentadecanone synthesis route, the method mainly has advantages of low cost andeasiness in acquisition of starting materials, the ketene intermediate shown as the formula (II) is obtained by high-selectivity reaction of cyclododecene and acryloyl chloride, and the integral synthesis route is simple and short in step, high in total yield and applicable to cyclopentadecanone industrial production.
Purification and Characterization of an Enone Reductase from Sporidiobolus salmonicolor TPU 2001 Reacting with Large Monocyclic Enones
Yamamoto, Kazunori,Oku, Yuko,Ina, Atsutoshi,Izumi, Atsushi,Doya, Masaharu,Ebata, Syuji,Asano, Yasuhisa
, p. 3697 - 3704 (2017/10/16)
We discovered a novel enone reductase from Sporidiobolus salmonicolor TPU 2001 (SsERD) and expressed the gene in Escherichia coli. The enzyme catalyzed the reduction of (E)-3-methylcyclopentadec-2-en-1-one (E-2), cyclopentadec-2-en-1-one (3), and cyclododec-2-en-1-one (4) to (S)-muscone (S-1), cyclopentadecan-1-one (5), and cyclododecan-1-one (6), respectively. The apparent Km and Vmax values for E-2 were estimated to be 4.9±0.4 μm and 100±1.4 nmol min?1 mg?1, respectively. The enzyme was specific to NADPH, and cysteine residues strongly affected the enzyme activity. The enzyme exhibited the highest activity at pH 8.0 and high stability in the pH range from 4.5 to 11.0. Using 10 mU of the enzyme, S-1 was synthesized from 0.1 mm E-2 with 94.8 % yield and 100 % enantiomeric excess by incubation at pH 7.0 and 30 °C for 60 min. We further successfully constructed an enone reductase with high specific activity by mutation of SsERD. The Y67A variant from SsERD exhibited 4.5 times higher specific activity and 3 times higher catalytic efficiency toward E-2. This is the first report of an enzyme catalyzing the reduction of carbon–carbon double bond of large monocyclic enones.
CIRCULAR ECONOMY METHODS OF PREPARING UNSATURATED COMPOUNDS
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Paragraph 0064, (2018/01/18)
Methods of preparing unsaturated compounds or analogs through dehydrogenation of corresponding saturated compounds and/or hydrogenation of aromatic compounds are disclosed.
Heterogeneous cobalt catalysts for the acceptorless dehydrogenation of alcohols
Shimizu, Ken-Ichi,Kon, Kenichi,Seto, Mayumi,Shimura, Katsuya,Yamazaki, Hiroshi,Kondo, Junko N.
, p. 418 - 424 (2013/03/29)
A series of transition metal(M)-loaded TiO2 catalysts (M/TiO2) and Co-loaded catalysts on various support materials were prepared by an impregnation method, followed by in situ H2-reduction at 400 °C, and tested for the acceptor-free oxidation of cyclododecanol in the liquid phase. Among the catalysts including noble metal catalysts, Co/TiO2 showed the highest activity. In the presence of Co/TiO 2 (0.1-3 mol%) the dehydrogenation of various aliphatic secondary alcohols proceeded to afford the corresponding ketones. The catalyst was recoverable and was reused after the H2-reduction treatment. Based on the spectroscopic characterization of the catalyst combined with the studies on the effect of the Co oxidation states on the catalytic activity, it is clarified that the surface metallic Co sites with electron deficiency are the catalytically active species.
Acceptor-free dehydrogenation of secondary alcohols by heterogeneous cooperative catalysis between Ni nanoparticles and acid-base sites of alumina supports
Shimizu, Ken-Ichi,Kon, Kenichi,Shimura, Katsuya,Hakim, Siddiki S.M.A.
, p. 242 - 250 (2013/04/10)
Nickel-nanoparticle-loaded θ-Al2O3 (Ni/θ-Al2O3), prepared by H2-reduction of NiO/θ-Al2O3, acts as an effective and reusable heterogeneous catalyst for acceptor-free dehydrogenation of alcohols in a liquid phase. Among various supports, amphoteric supports (such as θ-Al 2O3), having both acidic and basic sites, gave higher activity than acidic or basic supports. Among Ni/θ-Al2O 3 catalysts with different Ni particle sizes, turnover frequency (TOF) per surface Ni increases with decreasing Ni particle size. These results suggest that low-coordinated Ni0 sites and metal/support interfaces play important roles in the catalytic cycle. The reaction mechanism is investigated by in situ IR study combined with kinetic analysis (kinetic isotope effect), and the following mechanism is proposed: (1) reaction of an alcohol with Lewis acid (Alδ+)-base (AlOδ-) pair site of alumina yields an alkoxide on the Alδ+ site and a proton on the AlOδ- site, (2) CH dissociation of the alkoxide by Ni 0 site to form NiH and a ketone, and (3) protolysis of NiH by a neighboring proton to release H2 gas. The proposed mechanism provides fundamental reasons for the higher activity of Ni on the acid-base bifunctional support (Al2O3) than on basic and acidic ones.
Exaltone (=Cyclopentadecanone) from Isomuscone (=Cyclohexadecanone), a one-C-atom ring-contraction methodology via a stereospecific favorskii rearrangement: Regioselective application to (-)-(R)-muscone
Chapuis, Christian,Robvieux, Fabrice,Cantatore, Carole,Saint-Leger, Christine,Maggi, Laurent
experimental part, p. 428 - 447 (2012/05/07)
Treatment of cyclohexadecanone (1g; with I2 (2.2 mol-euqiv.) and KOH in MeOH) furnished the unsaturated (Z)-ester 2g in 83% yield, via a stereospecific Favorskii rearrangement (Scheme 1). Further treatment with 3-chloroperbenzoic acid (m-CPBA) afforded the unreported epoxy ester 3g (88% yield), which was cleaved in 33% yield to Exaltone (=cyclopentadecanone; 1f) with NaOH in MeOH/H2O and then HCl at 65°. This methodology was similarly extended to higher (C17) and lower (C15 to C11) cyclic ketone analogues, as well as regioselectively to (-)-(R)-muscone (5c) and homomuscone (5f) (Scheme 2). Olfactive properties of the corresponding macrocyclic 1-oxaspiro[2,n]alkanes and -alkenes 4 and 8, resulting from a Coreyi-Chaykovsky oxiranylation, are also presented. Copyright
Gold(III) complexes catalyze deoximations/transoximations at neutral pH
Isart, Carles,Bastida, David,Bures, Jordi,Vilarrasa, Jaume
experimental part, p. 3275 - 3279 (2011/05/12)
Golden solution: A neutral solution of AuBr3, containing [AuBr2(OH)2]- in equilibrium with [AuBr 3(OH)]- and [AuBr4]-, promotes the chemoselective hydrolysis of robust oximes into carbonyl compounds without racemization (see scheme). The food additive diacetyl acts as a NH 2OH-trapping agent, thus avoiding the formation of gold nanoparticles and allows the reaction to run catalytically. Copyright
