- Cyclopentadecanon preparation method
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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 0010; 0074-0075
(2018/03/26)
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- Exaltone (=Cyclopentadecanone) from Isomuscone (=Cyclohexadecanone), a one-C-atom ring-contraction methodology via a stereospecific favorskii rearrangement: Regioselective application to (-)-(R)-muscone
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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
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p. 428 - 447
(2012/05/07)
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- Gene encoding cyclododecanone monooxygenase
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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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- Diradical-promoted (n + 2 - 1) ring expansion: An efficient reaction for the synthesis of macrocyclic ketones
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(Chemical Equation Presented) A diradical-promoted (n + 2 - 1) ring expansion reaction based on vinyl side chain insertion (+2C) and decarbonylation (-1C) has been developed. Flash vacuum pyrolysis (FVP) of medium- and large-ring 2-trimethylsilyloxy-2-vinyl-cycloalkanones at 500-600°C affords the one-carbon ring-expanded cycloalkanones in good yields. Methyl groups on the vinyl moiety are transformed regiospecifically as corresponding α- and β-substituents, respectively. 2-Ethynyl precursor analogues react in a manner similar to give α,β-unsaturated cyclic ketones.
- Rueedi, Georg,Oberli, Matthias A.,Nagel, Matthias,Hansen, Hans-Jurgen
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p. 3179 - 3181
(2007/10/03)
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- Silica Gel Supported γ-Picolinium Chlorochromate; a New and Efficient Reagent for Selective Conversion of Alcohols and Oximes into Carbonyl Compounds under Mild and Non-Aqueous Conditions
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The preparation of silica gel supported γ-picolinium chlorochromate and its application as an efficient reagent for selective oxidation of oximes and alcohols into carbonyl compounds is reported. The trimethylsilyloxy and ester groups survived under the reaction conditions.
- Salehi,Khodaei,Yazdanipoor
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p. 1281 - 1286
(2007/10/03)
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- A novel, short and repeatable two-carbon ring expansion reaction by thermo-isomerization: Easy synthesis of macrocyclic ketones
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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
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p. 275 - 279
(2007/10/03)
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- Short and versatile two-carbon ring expansion reactions by thermo-isomerization: Novel straightforward synthesis of (±)-muscone, nor- and homomuscones, and further macrocyclic ketones
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Thermo-isomerization of 1-vinyl substituted medium-and large-ring cycloalkanol derivatives in a flow reactor system at temperatures of 600°C to about 650°C leads directly to the ring-expanded macrocyclic ketones. Alkyl substituents at the vinylic moiety are transferred locospecifically to the ring-expanded ketone as corresponding α-, and β-substituents, respectively. This novel thermal 1,3-C shift reaction therefore provides a new access to short syntheses of many alkyl-substituted macrocyclic ketone derivatives [e.g. (±)-muscone and analogues] in a systematic manner.
- Nagel, Matthias,Hansen, Hans-Jürgen,Fráter, Georg
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p. 280 - 284
(2007/10/03)
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- Total synthesis of cytotoxic sponge alkaloids motuporamines A and B
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The synthesis of two sponge alkaloids, Motuporamines A and B is reported. The key step involved a reductive amination using sodium triacetoxyborohydride.
- Baldwin, Jack E.,Vollmer, Heidi R.,Lee, Victor
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p. 5401 - 5404
(2007/10/03)
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- New Method for Generation of β-Oxido Carbenoid via Ligand Exchange Reaction of Sulfoxides: A Versatile Procedure for One-Carbon Homologation of Carbonyl Compounds
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A new procedure for one-carbon homologation of carbonyl compounds is described.The method is based on the rearrangement of β-oxido carbenoid which is generated via the ligand exchange reaction of the sulfinyl group of α-chloro β-hydroxy sulfoxide with tert-butyllithium.Addition of the carbanion of aryl 1-chloroalkyl sulfoxides to carbonyl compounds gave the adducts in good yields.The β-oxido carbenoid rearrangement of the adducts gave one-carbon homologated carbonyl compounds having an α-alkyl substituent.A similar reaction of the adducts derived from carbonyl compounds with chloromethyl p-tolyl sulfoxide yielded a procedure for a methylene insertion.The stereochemistry of the β-oxido carbenoid rearrangenment is also discussed.
- Satoh, Tsuyoshi,Itoh, Norifumi,Gengyo, Kaoru,Takada, Sae,Asakawa, Naoyuki,et al.
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p. 11839 - 11852
(2007/10/02)
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- New Methods and Reagents in Organic Synthesis. 18. Homologation of Ketones with Trimethylsilyldiazomethane (TMSCHN2)
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Trimethylsilyldiazomethane (TMSCHN2) easily reacts with various ketones in the presence of boron trifluoride etherate in methylene chloride solution to give chain- or ring-homologated ketones, and can be used as a stable and safe substitute for hazardous diazomethane.The reaction proceeds below 0 deg C during 1-4 h, and permits much more efficient homologation than can be achieved with diazomethane.
- Hashimoto, Norio,Aoyama, Toyohiko,Shioiri, Takayuki
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p. 119 - 124
(2007/10/02)
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- 186. Steric Effects on Reaction Rates. Rate and Equilibrium Constants for Oxidation of Cyclanols
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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
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p. 1759 - 1766
(2007/10/02)
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- NEW METHODS AND REAGENTS IN ORGANIC SYNTHESIS. 10. TRIMETHYLSILYLDIAZOMETHANE (TMSCHN2), A NEW, STABLE, AND SAFE REAGENT FOR THE HOMOLOGATION OF KETONES
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Homologation of ketones can be achieved with trimethylsilyldiazomethane (TMSCHN2) which is a stable and safe substitute for hazardous diazomethane.
- Hashimoto, Norio,Aoyama, Toyohiko,Shiori, Takayuki
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p. 4619 - 4622
(2007/10/02)
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- Oxatricyclo compounds useful as perfuming agents
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New oxygenated tricyclic derivatives are disclosed as being useful as perfuming and flavoring agents for the preparation of perfumes and perfumed articles and for the manufacture of artificial flavors, flavored foodstuffs, animal feeds, beverages, pharmaceutical preparations and tobacco products.
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