21944-95-6Relevant academic research and scientific papers
Cyclopropylcarbinyl radicals as three-carbon insertion units: Easy synthesis of C-15 macrocyclic ketones by three-carbon ring expansion
Rüedi, Georg,Hansen, Hans-Jürgen
, p. 5143 - 5145 (2004)
Thermal isomerization of cyclic 3-cyclopropyl ketones under FVP conditions at 620°C provides a new and convenient route to δ,ε-unsaturated cycloalkanones. The synthetic potential of this novel three-carbon ring expansion has been demonstrated by the synthesis of (±)-muscone from inexpensive C-12 starting material.
A Facile Synthesis of 1,2-Divinylcycloalkanols and Their Behavior in the Oxy-Cope Rearrangement
Kato, Tetsuya,Kondo, Hisao,Nishino, Masaki,Tanaka, Minoru,Hata, Go,Miyake, Akihisa
, p. 2958 - 2961 (1980)
The reaction of 2-chlorocycloalkanones with vinylmagnesium chloride gives 1,2-divinylcycloalkanols.Divinylation proceeds via a rearrangement of initially formed 2-chloro-1-vinylcycloalkanols to 2-vinylcycloalkanones followed by further vinylation of 2-vinylcycloalkanones.Thermal sigmatropic rearrangement of 1,2-divinylcycloalkanols gives 5-cycloalken-1-ones in good yields.The influence of the size of rings on the reaction pathways is discussed.
A practical method for alcohol oxidation with aqueous hydrogen peroxide under organic solvent- and halide-free conditions
Sato, Kazuhiko,Aoki, Masao,Takagi, Junko,Zimmermann, Klaus,Noyori, Ryoji
, p. 2287 - 2306 (2007/10/03)
A catalytic system consisting of sodium tungstate and methyltrioctylammonium hydrogensulfate effects oxidation of simple secondary alcohols to ketones using 3 - 30% H2O2 without any organic solvents. The oxidation can be conducted under entirely halide-free, mildly acidic conditions. A combination of tungstic acid and an appropriate quaternary ammonium salt also effects the alcohol dehydrogenation. The organic/aqueous biphasic reaction allows easy product/catalyst separation. The turnover number, defined as tools of product per mol of catalyst, approaches 77700 (2- octanol) or 179000 (1-phenylethanol), two orders of magnitude higher than any previously reported. Ester, alkyl and t-butyldimethylsilyl ether, epoxy, carbonyl, N-alkyl carboxamide, and nitrile groups are tolerated under the reaction conditions. Secondary alcohols are preferentially oxidized over terminal olefins. Primary alkanols are oxidized directly to carboxylic acids in a moderate to high yield. Benzylic alcohols are selectively oxidized to benzaldehydes or benzoic acids under suitable conditions. This method is high-yielding, clean, safe, operationally simple, and cost-effective, and therefore suitable for practical organic synthesis. The mechanistic origin of the catalytic efficiency is discussed.
TRANSPOSITION OXY-COPE ASSISTEE PAR LE TRIFLUOROACETATE MERCURIQUE EN QUANTITE STOECHIOMETRIQUE ET EN QUANTITE CATALYTIQUE
Bluthe, Norbert,Malacria, Max,Gore, Jacques
, p. 3277 - 3284 (2007/10/02)
Tertiary 1,5-hexadien-3-ols are transformed at room temperature into δ-ethylenic ketones in 35-90percent yields under two sets of conditions: treatment with one molar equivalent of mercuric trifluoroacetate followed by demercuration of the intermediate α-mercuro ketone with sodium borohydride; and treatment with 0.2 molar equivalent of the same salt in the presence of one molar equivalent of lithium trifluoroacetate or trifluoromethansulfonate.The reactions are highly stereoselective, the E isomer of the ketone forming 80-95percent of the product.The highest selectivity was observed under the second conditions.
