cas 502-72-7, Cyclopentadecanone | Articles data

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Synthesis of Cyclopentadecanone by Ring Contraction of Cyclohexadecanone
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.
Kato, Tetsuya,Kondo, Hisao,Miyake, Akihisa
p. 823 - 824
(1980)
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Photochemical Transformations with Iodine Azide after Release from an Ion-Exchange Resin
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.
Dr?ger, Gerald,K?sel, Teresa,Kirschning, Andreas,Schulz, G?ran
supporting information
p. 12376 - 12380
(2020/05/08)

Cyclopentadecanone preparation method
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.
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Paragraph 0084; 0085; 0089

(2018/04/28)

Cyclopentadecanon preparation method
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.
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Paragraph 0014; 0074-0075

(2018/03/26)

CIRCULAR ECONOMY METHODS OF PREPARING UNSATURATED COMPOUNDS
Methods of preparing unsaturated compounds or analogs through dehydrogenation of corresponding saturated compounds and/or hydrogenation of aromatic compounds are disclosed.
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Paragraph 0064

(2018/01/18)

Purification and Characterization of an Enone Reductase from Sporidiobolus salmonicolor TPU 2001 Reacting with Large Monocyclic Enones
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.
Yamamoto, Kazunori,Oku, Yuko,Ina, Atsutoshi,Izumi, Atsushi,Doya, Masaharu,Ebata, Syuji,Asano, Yasuhisa
p. 3697 - 3704
(2017/10/16)

Heterogeneous cobalt catalysts for the acceptorless dehydrogenation of alcohols
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.
Shimizu, Ken-Ichi,Kon, Kenichi,Seto, Mayumi,Shimura, Katsuya,Yamazaki, Hiroshi,Kondo, Junko N.
p. 418 - 424
(2013/03/29)

Acceptor-free dehydrogenation of secondary alcohols by heterogeneous cooperative catalysis between Ni nanoparticles and acid-base sites of alumina supports
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.
Shimizu, Ken-Ichi,Kon, Kenichi,Shimura, Katsuya,Hakim, Siddiki S.M.A.
p. 242 - 250
(2013/04/10)

Exaltone (=Cyclopentadecanone) from Isomuscone (=Cyclohexadecanone), a one-C-atom ring-contraction methodology via a stereospecific favorskii rearrangement: Regioselective application to (-)-(R)-muscone
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
Chapuis, Christian,Robvieux, Fabrice,Cantatore, Carole,Saint-Leger, Christine,Maggi, Laurent
p. 428 - 447
(2012/05/07)

Gold(III) complexes catalyze deoximations/transoximations at neutral pH
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
Isart, Carles,Bastida, David,Bures, Jordi,Vilarrasa, Jaume
experimental part
p. 3275 - 3279
(2011/05/12)

Gene encoding cyclododecanone monooxygenase
The invention relates to a new strain of Pseudomonas putida (designated as HI-70) and to the isolation, cloning, and sequencing of a cyclododecanone monooxygenase-encoding gene (named cdnB) from said strain. The invention also relates to a new cyclododecanone monooxygenase and to a method of use of the cyclododecanone monooxygenase-encoding gene.
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(2008/06/13)

METHOD FOR PRODUCING MACROCYCLIC KETONES BY MEANS OF DIECKMANN CONDENSATION IN THE GAS PHASE
The invention relates to a method for producing macrocyclic ketones of general formula (I) by direct cyclisation of compounds of general formula (II) in the gas phase on a heterogeneous catalyst. In general formula (I), X represents a monounsaturated or polyunsaturated or saturated C10-C17 alkyl radical which can be optionally substituted by a C1-C6 alkyl radical, and in general formula (II), R1, R2 can respectively be the same or different and represent hydrogen or C1-C6 alkyl, and X has the above-mentioned designation.
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Page/Page column 5

(2008/06/13)

Conversion of ketoximes to ketones with trimethylphosphine and 2,2′-dipyridyl diselenide
Use of trimethylphosphine (Me3P) and 2,2′-dipyridyl diselenide (PySeSePy) is an excellent method for the conversion of ketoximes to the corresponding ketones, since yields higher than 90% are obtained at rt within a fewminutes (or hours for the more reluctant substrates, which do not react with Bu3P/PhSSPh). In the simplest cases, the reaction can be completed with 30mol% of PySeSePy, provided that an excess of phosphine is present in the reaction medium.
Martín, Manuel,Martínez, Gabriel,Urpí, Fèlix,Vilarrasa, Jaume
p. 5559 - 5561
(2007/10/03)

From (E)- and (Z)-ketoximes to N-sulfenylimines, ketimines or ketones at will. Application to erythromycin derivatives
Reactions of (E)- and (Z)-ketoximes with trialkylphosphines and diphenyl disulfide (PhSSPh) have been compared to gain insight into the mechanisms involved and their potential applications. N-Sulfenylimine isomers and ketimines have been spectroscopically characterised. Both the E and Z isomers of erythromycin A oxime, when treated with Bu3P and PhSSPh (1:4:8 ratio), give the same N-phenylsulfenyl ketimine (of configuration E) as the major compound, whereas with Bu3P or Me3P and PySeSePy (1:8:4 ratio) afford the imine in good yield. Clarithromycin oxime behaves similarly.
Esteban, Jorge,Costa, Anna M.,Urpí, Fèlix,Vilarrasa, Jaume
p. 5563 - 5567
(2007/10/03)

Production method of ketone compound
A method for producing a ketone, particularly a macrocyclic ketone, from a 2-hydroxycycloalkanone having from 12 to 18 carbon atoms by efficiently dehydrating and reducing the acyloin in a single reaction vessel. A method for producing a ketone compound, which comprises dehydrating and reducing an acyloin in the coexistence of an acid catalyst and a reduction catalyst and in the presence of hydrogen, particularly using a 2-hydroxycycloalkanone having from 12 to 18 carbon atoms as the acyloin.
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Page 3

(2008/06/13)

Bis(pyridine)iodonium tetrafluoroborate (IPy2BF4): A versatile oxidizing reagent
The use of bis(pyridine)iodonium tetrafluoroborate (IPy2BF 4) as an oxidizing agent towards different types of alcohols is reported. The observed reactivity involves different reaction pathways, as a function both of the structures of the starting materials and of the experimental conditions. Interestingly, the title iodine-containing compound is capable of a tuneable reaction with simple cycloalkanols, providing straight and selective access either to ω-iodocarbonyl compounds or to ketones, a previously unreported and chemoselective range of oxidation potential. Furthermore, appropriate conditions for the preparation of aldehydes and esters from primary alcohols by easily performed experimental procedures were also established. The β-scission reactions of cycloalkanols and the α-oxidation processes of primary, secondary and benzylic alcohols are discussed.
Barluenga, Jose,Gonzalez-Bobes, Francisco,Murguia, Marcelo C.,Ananthoju, Sreenivasa R.,Gonzalez, Jose M.
p. 4206 - 4213
(2007/10/03)

Productive chloroarene C-Cl bond activation: Palladium/phosphine-catalyzed methods for oxidation of alcohols and hydrodechlorination of chloroarenes
The palladium/phosphine-catalyzed productive chloroarene C-Cl bond activation provides general, efficient, and functional group friendly methods for the selective oxidation of alcohols and the hydrodechlorination of chloroarenes.
Bei, Xiaohong,Hagemeyer, Alfred,Volpe, Anthony,Saxton, Robert,Turner, Howard,Guram, Anil S.
p. 8626 - 8633
(2007/10/03)

Aerobic oxidation of cycloalkanes, alcohols and ethylbenzene catalyzed by the novel carbon radical chain promoter NHS (N-hydroxysaccharin)
Replacement of Ishii's N-hydroxyphthalimide (NHPI) with the novel carbon radical chain promoter N-hydroxysaccharin (NHS) affords, in combination with metal salts, notably Co, or other additives, selective catalytic autoxidation of hydrocarbons, alcohols and alkylbenzenes under mild conditions (25-100°C, O2 1 atm). The effects of solvent, temperature and the nature of the additives were investigated to give an optimised oxidation protocol for the various systems. The NHS/Co combination was more reactive than NHPI/Co in the autoxidation of cycloalkanes. In contrast, the opposite order of reactivity was observed in the autoxidation of ethylbenzene and alcohols. It is suggested, on the basis of bond dissociation energy (BDE) considerations, that this is a result of a change in the rate-limiting step with the more reactive ethylbenzene and alcohol substrates. In the autoxidation of the model cycloalkane, cyclododecane, the best results (90% selectivity to a 4:1 mixture of alcohol and ketone at 24% conversion) were obtained with NHS/Co(acac)3 in PhCF3 at 80°C. Competition experiments revealed that, in contrast to what is commonly believed, formation of the dicarboxylic acid by ring opening is not a result of further oxidation of the ketone product. It is suggested that ring opened products are a result of β-scission of the cycloalkoxy radical formed via (metal-catalysed) decomposition of the hydroperoxide. This is suppressed in the presence of NHS (or NHPI) which efficiently scavenge the alkoxy radicals.
Baucherel, Xavier,Gonsalvi, Luca,Arends, Isabel W. C. E.,Ellwood, Simon,Sheldon, Roger A.
p. 286 - 296
(2007/10/03)

A facile electrochemical approach for the synthesis of macrocyclic alkanones
The synthesis of macrocyclic alkanones, viz. cyclotetradecanone 4a, cyclohexadecanone 4b, cyclooctadecanone 4c, cyclopentadecanone 4d and cycloheptadecanone 4e have been carried out by using Kolbe symmetrical/unsymmetrical dimerization followed by cyclization in Na-xylene and subsequent reduction with Zn-HCI in 70-80% yield. The products of anodic cross coupling have been separated by column chromatography over silica gel (60-120 mesh) by eluting with benzene-methanol (95: 5). An effort has been made to optimize the electrochemical step by investigating the effect of different parameters, viz. degree of partial neutralization, current density and electrode material. The products have been characterised by elemental analyses and IR and 1H NMR spectral data.
Singh, Arpita,Singhal, Nishi,Agrawal, Hemlata,Yadav, Ashok K.
p. 423 - 426
(2007/10/03)

A novel, short and repeatable two-carbon ring expansion reaction by thermo-isomerization: Easy synthesis of macrocyclic ketones
A novel two-carbon ring enlargement procedure, in which medium- and large-ring 1-vinylcycloalkanols are thermoisomerized in a flow reactor system at temperatures of 600°C to about 650°C, produces the isomeric ring-expanded cycloalkanones directly and efficiently. This two-step ring expansion protocol can easily be applied several times successively. For e.g., the musk odorant cyclopentadecanone (Exaltone?) is prepared from cycloundecanone in two repetitive cycles. Thermo-isomerization of the corresponding ethynylic cycloalkanols gives in moderate yields the bishomologous α,β-unsaturated macrocyclic (E)-2-cycloalkenones. A reaction mechanism via alkyl hydroxyallyl biradical intermediates is proposed.
Nagel, Matthias,Hansen, Hans-Ju?rgen,Fra?ter, Georg
p. 275 - 279
(2007/10/03)

Macrocyclic ketones as fragrance materials and methods for making same
Novel macrocyclic diene ketone compounds useful as fragrance materials are described having the following general formula (I): where R1, R2, R3and R4are each either a hydrogen atom or a C1to C4alkyl, a is the integer 1 or 2 and b is an integer in a range from 1 to 6. Novel pathways are described for synthesizing these macrocyclic diene ketones, as well as saturated and mono-unsaturated macrocyclic ketones having the following general formula (IV): where R1, R2, R3and R4are each independently a hydrogen atom or a C1to C4alkyl, a is the integer 1 or 2 and b is an integer in a range from 1 to 6.
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(2008/06/13)

Process for cooxidizing organic compounds, process for producing epoxy compounds and process for producing esters or lactones
According to the inventive co-oxidation process of organic compounds, (A) a compound selected from (A1) a compound having a non-aromatic ethylenic bond and (A2) a ketone or an alcohol corresponding to the ketone is oxidized by molecular oxygen in the presence of N-hydroxyphthalimide or another imide compound and in the coexistence of (B) a compound oxidizable by the imide compound and oxygen and different from the compound (A). As the compound (B), (a) primary or secondary alcohols (e.g., benzhydrol, cyclohexanol), (b) compounds each having a carbon-hydrogen bond at the adjacent position to an unsaturated bond (e.g., tetralin, ethylbenzene) and the like can be used. According to this process, a corresponding epoxy compound from the compound (A1) having a non-aromatic ethylenic bond, and a corresponding ester or lactone from the ketone or its corresponding alcohol (A2) can be obtained in satisfactory yields.
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(2008/06/13)

Electroorganic synthesis 65. Anodic homocoupling of carboxylic acids derived from fatty acids
Fatty acid derived carboxylic acids with double bonds, hydroxy-, amino-, keto-, ester- and epoxy groups are anodically coupled to dimers (Kolbe electrolysis) in 29 to 81% yield and up to a 2.5 mol scale. Problems due to the low conductivity of fatty acid salts were overcome by the use of a flow cell with a narrow electrode gap. Fatty acids with branched alkyl chains gave dimers with interesting emulsifying properties. Dimethyl hexadecanedioate, accessible from methyl azelate, could be cyclized and further converted into homomuscone and muscone in a few steps. A commercial mixture of dimeric fatty acids (C36-dicarboxylic acids) has been coupled to give C70-diesters. Acta Chemica Scandinavica 1998. Part 64: Nielsen, M. F., Batanero, B.,.
Weiper-Idelmann, Andreas,Aus Dem Kahmen, Martin,Schaefer, Hans J.,Gockeln, Marianne
p. 672 - 682
(2007/10/03)

Envirocat EPZG as a New Heterogeneous Catalyst for the Regeneration of Ketones from Their Tosylhydrazones
Envirocat EPZG represents a new heterogeneous catalyst for ketones regeneration from their tosylhydrazones. Aldehyde tosylhydrazones were less reactive under these conditions, allowing to perform a selective regeneration of ketone in the presence of both ketone and aldehyde tosylhydrazones.
Ballini, Roberto,Bosica, Giovanna,Maggi, Raimondo,Sartori, Giovanni
p. 795 - 796
(2007/10/03)

Chemoselective conversion of conjugated nitroalkenes into ketones by sodium borohydride-hydrogen peroxide: A new synthesis of 4-oxoalkanoic acids, dihydrojasmone and (±)exo-brevicomin
A new, simple, cheap, and practical procedure for the direct transformation of α,β-unsaturated nitroalkenes into ketones has been realized by the NaBH4/H2O2 system. By this method, other functional groups such as C-C double bonds, ketals or aromatic nitro groups were preserved. Application of this methodology to the preparation of 4-oxoalkanoic acids, dihydrojasmone, and (±)-exobrevicomin is also reported.
Ballini,Bosica
p. 723 - 726
(2007/10/02)

Conversion of the Carbonyl Group to CF2 Using IF
A novel method for the transformation of CO -> CF2 is described.The easily made hydrazone derivatives of the carbonyl moiety are reacted under mild conditions with IF prepared directly from the corresponding elements.Various hydrazones have been examined and compared with each other.Unsubstituted ones are usually the most suitable although they are not always easy to purify and store.N-Methyl- and N,N-dimethylhydrazones also give quite satisfactory results.The more easily made dinitrophenyl hydrazones (DNPs), semicarbazones, and tosylhydrazones also react, but the yields of the desired CF2 compounds are usually lower.Oximes could also be successfully reacted.The two main byproducts of the reaction are the parent carbonyl compounds, which can be recycled, and the α-iododifluoro derivatives.The latter upon treatment with LiAlH4 or Bu3SnH were reduced to the desired product, thus increasing the overall yields.
Rozen, Shlomo,Zamir, Dov
p. 4695 - 4700
(2007/10/02)

A New Synthesis of Muscone and Exaltone. The Enamine Approach of Ring-Enlargement Reaction
Key reaction in the synthesis of the title compounds in the treatment of the aldehydes 6 and 7 (obtained from 1) with a primary amine, e.g. pentylamine, in EtOH at room temperature.After stirring overnight, the products 8 and 9, respectively, are obtained in good yields.Both are enlarged by three ring members and can be transformed to Exalton (12) and (+/-)-muscone, (13), respectively.
Bienz, Stefan,Hesse, Manfred
p. 1704 - 1707
(2007/10/02)

Synthesis of macrocyclic ketones by ring-enlargement reactions; A new path to (±)-muscone
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Bienz,Hesse
p. 2146 - 2151
(2007/10/02)

A SIMPLE NEW GENERAL SYNTHESIS OF MACROCYCLIC KETONES: A NEW ENTRY TO THE SYNTHESIS OF EXALTONE AND (+/-)-MUSCONE
We describe an efficient new synthesis of 15-membered cyclic ketones, exaltone and (+/-)-muscone, based on a three-carbon annelation of cyclic ketones followed by the regioselective radical cleavage of the fused bond of the resulting bicyclic systems.
Suginome, Hiroshi,Yamada, Shinji
p. 3963 - 3966
(2007/10/02)

Process for preparing macrocyclic ketones
An improvement in a process for preparing a macrocyclic ketone having from 12 to 18 carbon atoms which comprises intramolecular cyclization of a lower alcohol diester of a straight chain alkanedicarboxylic acid having from 12 to 18 carbon atoms by acyloin condensation and reduction of the resulting 2-hydroxycycloalkanone is disclosed. The improvement comprises conducting the acyloin condensation in a water-immiscible organic solvent having a boiling point of not lower than 40°C., subjecting the resulting organic solvent solution containing the 2-hydroxycycloalkanone to reduction, and conducting the reduction in the copresence of said organic solvent and water. The macrocyclic ketone can be prepared at high efficiency.
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(2008/06/13)

Process for preparing macrocyclic ketones
An improvement in a process for preparing a macrocyclic ketone having from 12 to 18 carbon atoms which comprises intramolecular cyclization of a lower alcohol diester of a straight chain alkanedicarboxylic acid having from 12 to 18 carbon atoms by acyloin condensation and reduction of the resulting 2-hydroxycycloalkanone is disclosed. The improvement comprises conducting the acyloin condensation in a water-immiscible organic solvent having a boiling point of not lower than 40°C, subjecting the resulting organic solvent solution containing the 2--hydroxycycloalkanone to reduction, and conducting the reduction in the copresence of said organic solvent and water. The macrocyclic ketone can be prepared at high efficiency.
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(2008/06/13)

SELECTIVE MIXED COUPLING OF CARBOXYLIC ACIDS-III. SYNTHESIS OF CYCLOPENTADECANONE FROM CYCLIC TETRAACYL DIPEROXIDES
Cyclopentadecanone (1b) and cyclotetradecane (1a) were prepared in 53 and 83percent yield by thermolysis or photolysis of the cyclic tetraacyl diperoxides 4b and 4a.The compounds 4a, b were obtained from diperoxydodecanedioic acid (3) and the acyl chloride 5a or the dicarboxylic acid 2b.
Feldhues, Michael,Schafer, Hans. J.
p. 1285 - 1290
(2007/10/02)

NEW SYNTHETIC 'TRICKS'. ADVANTAGES OF USING TRIETHYLPHOSPHINE IN SOME PHOSPHORUS-BASED REACTIONS
It is shown that Et3P can advantageously replace Ph3P, Bu3P, and other P(III) reagents in phosphazene reactions (amide and phthalimide formation) and disulphide-cleavage-based reactions (reduction of disulphides, thioester formation, and oxime hydrolysis).
Urpi, Felix,Vilarrasa, Jaume
p. 4623 - 4624
(2007/10/02)

A Synthetic Equivalent for the Butadienyl Carbonium Ion: Use of 4-(Trimethylsilyl)but-2-ynal for Preparation of 1,3-Dienes and Macroexpansion of Cyclic Ketones
4-(Trimethylsilyl)but-2-ynal (3) is a synthetic equivalent for the butadienyl carbonium ion and can be used for preparation of terminal 1,3-dienes and for macroexpansion of cyclic ketones.
Angoh, A. Gaetan,Clive, Derrick L. J.
p. 534 - 536
(2007/10/02)

Hydroboration. 67. Cyclic Hydroboration of Acyclic α,ω-Dienes with 9-Borabicyclononane/Borane-Dimethyl Sulfide
Hydroboration of acyclic α,ω-dienes, 1,3-butadiene, 1,4-pentadiene, 1,5-hexadiene, 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene, 1,11-dodecadiene, and 1,13-tetradecadiene, with 2 molar equiv of 9-borabicyclononane (9-BBN), followed by redistribution of the resulting dumbbell-shaped trialkylboranes with 1 molar equiv of borane-methyl Sulfide complex (BMS), has been investigated.With 1,3-butadiene, the initial redistribution product, the five-membered boracyclane, borolane, underwent a rapid ring-opening reaction to give the known 1,6-diboracyclodecane. 1,4-Pentadiene and 1,5-hexadiene afforded the corresponding boracyclanes, borinane and borepane, in quantitative yields.With all other dienes, the initial redistribution products were polymeric.They were converted to the methyl esters by treatment with methanol, and these products were depolymerized into cyclic derivatives in 88-98percent yield by vacuum distillation at 175-200 deg C.In every case the cyclization was accompanied by varying amounts of isomerization so that the major products were both the parent B-methoxyboracyclane and the corresponding B-methoxy-2-n-alkylborinane.Thus, 1,6-heptadiene afforded B-methoxyborocane and B-methoxy-2-ethylborinane in 3:1 ratio and a total yield of 95percent.With 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene and 1,11-dodecadiene, the isomerized product constituted the major constituent of the distillate. 1,13-Tetradecadiene afforded the parent boracyclane and the isomer in a 47:53 ratio and a combined yield of 82percent.The B-methoxyboracyclanes were converted to the corresponding cyclic ketones by the DCME reaction in 55-65percent yield.
Brown, Herbert C.,Pai, Ganesh G.,Naik, Ramachandra G.
p. 1072 - 1078
(2007/10/02)

STRATEGY FOR CYCLOPENTENONE ANNULATION OF OLEFINS: A GENERAL PROTOCOL FOR BICYCLOENONE SYNTHESIS
Several bicyclic α-chloro enones obtained through Greene annulation of cyclic olefins are shown to undergo efficient, two step, enone transposition via Luche reduction and aq. formic acid treatment.Application of this methodology to the formal synthesis of exaltone and (+/-)-muscone is described.
Mehta, Goverdhan,Rao, K. Srinivas
p. 1839 - 1842
(2007/10/02)

A Novel Three-Carbon Ring Expansion Sequence. Synthesis of ExaltoneR and (+/-)-Muscone
Intramolecular Grignard-type reaction of the bromolactones 3 and 8 affords the macrocycles 10, 11, 12 and 13, 14, 15, respectively.More efficiently, 10 and 13 are obtaine by intramolecular nucleophilic attack of the carbanions derived from the sulfonyl lactones 20 and 22 and in situ reduction of the intermediate sulfones 21 and 23.The macrocyclic hydroxy ketones 10 and 13 are converted into ExaltoneR (2) muscone(1), respectively.
Fehr, Charles
p. 2512 - 2518
(2007/10/02)

Process for purifying macrocyclic ketones
A macrocyclic ketone having a 15- to 17-membered ring is produced from an α,ω-long chain dicarboxylic acid ester by the Dieckmann condensation reaction, followed by hydrolysis/decarboxylation reaction and then purification. The macrocyclic ketone is purified by subjecting the ketone to steam distillation in the presence of a non-volatile base.
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(2008/06/13)

An Asymmetric Synthesis of Acyclic and Macrocyclic α-Alkyl Ketones. The Role of (E)- and (Z)-Lithioenamines
Metalation and alkylation of chiral imines derived from C10, C12, and C15 cyclic ketones gave, under kinetic metalation conditions, 2-alkylcycloalkanones of absolute configuration opposite to that formed from thermodynamic metalation.Thus, (S)-(-)-2-methylcyclododecanone is formed kinetically in 60percent ee, whereas (R)-(+)-methylcyclododecanone is reached in 80percent ee under thermodynamic conditions.In a similar fashion, acyclic ketones 20, via their chiral imines 17, are alkylated enantioselectively under both kinetic and thermodynamic modes.The kinetic metalation gives exclusively the (Z)-lithioenamines (19), while reflux of this lithio anion gives only the (E)-lithioenamine (19).Chiral α-substituted ketones are produced in 18-97percent ee.
Meyers, A. I.,Williams, Donald R.,White, Steven,Erickson, Gary W.
p. 3088 - 3093
(2007/10/02)

186. Steric Effects on Reaction Rates. Rate and Equilibrium Constants for Oxidation of Cyclanols
Equilibrium constants for oxidations of cyclanols by cyclohexanone in benzene have been determined in the presence of aluminium isopropoxide.The free energies of the equilibrium (ΔGox) are correlated with equilibrium constants for dissociation of cyanohydrins, rate constants for cyclanol oxidation with chromic acid, ketone reduction with sodium borohydride and trifluoroethanolysis of tosylates.
Paul, Mueller,Blanc, Jacky
p. 1759 - 1766
(2007/10/02)