4591-28-0Relevant articles and documents
SYNTHESIS AND VALENCE BOND ISOMERIZATION OF CYCLOOCTATROPOLONE
Oda, Mitsunori,Morita, Noboru,Asao, Toyonobu
, p. 1165 - 1168 (1981)
Cyclooctatropolone (4) was synthesized by hydrolysis of an adduct of 1H-cyclopentacyclooctene and dichloroketene.The tropolone was found to exist as a mixture of valence bond isomers (4a) and (4b).
Halogenated Ketenes. 36. Reactions of Chloroketenes with Ketene Acetals
Brady, William T.,Watts, Ronald D.
, p. 4047 - 4050 (1981)
The products of the reactions of ketenes and ketene acetals are dependent upon substitution in the ketene acetals.Dichloroketene reacts with dimethylketene dimethyl acetal to regiospecifically yield the cyclobutanone.The reaction of methylchloroketene and ketene diethyl acetal yields an acyclic product, an acylketene acetal.Chloro-, dichloro-, and methylchloroketenes react with O-silylated ketene acetals to yield acyclic unsaturated esters.Dichloroketene reacts with the acylketene acetal, (α-chloropropionyl)ketene diethyl acetal, to yield a (4 + 2) cycloaddition product, a δ-lactone.All of these results are consistent with a two-step process involving a dipolar intermediate.
Efficient approach to 1,2-diazepines via formal diazomethylene insertion into the C-C bond of cyclobutenones
Sugimoto, Kenji,Hayashi, Rie,Nemoto, Hideo,Toyooka, Naoki,Matsuya, Yuji
supporting information; experimental part, p. 3510 - 3513 (2012/07/31)
Efficient monocyclic 1,2-diazepine formation via a tandem electrocyclization reaction of cyclobutenones with lithiodiazoacetate is demonstrated. The reaction proceeds through an oxy anion-accelerated 4π-ring opening of cyclobutene followed by an 8π-ring closure of the resultant oxy anion-substituted diazo-diene under mild conditions to furnish a 1,2-diazepine via formal diazomethylene insertion into the C-C bond of cyclobutenone.
A new approach to the synthesis of the 17β-butenolide fragment of cardenolides
Paryzek, Zdzislaw,Blaszczyk, Krzysztof
, p. 5913 - 5914 (2007/10/03)
A new, efficient synthesis of the 17β-butenolide fragment characteristic of cardenolides is effected by [2 + 2]-cycloaddition of dichloroketene to 3β-acetoxypregna-5,20-diene, as a key step.
Flash Vacuum Thermolysis of Four Membered Ring Containing Nitrogen Atom. Part III. Thermal Decomposition of β-Lactams
Bartnik, R.,Lesniak, S.
, p. 2605 - 2612 (2007/10/02)
The thermal decomposition of β-lactams under FVT conditions was studied. It has been found that the regiochemistry of the ring cleavage depends on the nature of substituents. 1,4-Diradical stepwise mechanism of these reactions has been postulated. Key words: β-lactams, flash vacuum thermolysis
Cycloadditions of 2,4,6-Cycloheptatriene-1-imines with Chloroketenes: Facile and High-Yield One-Pot Synthesis of 1-Azaazulen-2(1H)-ones
Ito, Kazuaki,Saito, Katsuhiro,Takahashi, Kensuke
, p. 812 - 816 (2007/10/02)
Simple heating of mixtures of N-arylcycloheptatriene-1-imines and acyl chlorides in the presence of an excess amount of triethylamine afforded 1-azaazulen-2(1H)-ones in high yields.The intermediacy of the cycloadducts between the 2,4,6-cycloheptatriene-1-imines and ketenes were confirmed by their isolations.Analogous results were obtained with tropone hydrazones.
STERICALLY SCREENED HALOGENOCYCLOBUTANONES VIII. ADDITION OF DICHLOROKETENE TO METHYLENECYCLOPROPANES SUBSTITUTED AT THE DOUBLE BOND
Donskaya, N. A,,Bessmertnykh, A. G.,Lukovskii, B. A.,Kisina, M. Yu.,Ryabova, M. A.
, p. 2249 - 2253 (2007/10/02)
-Cycloaddition of dichloroketene to metylenecyclopropanes substituted at the double bond takes place regiospecifically with the formation of spirohexanones, containing a carbonyl group at position 4.Under electron impact the obtained compounds undergo dissociation mainly into substituted dichloroethylene and cyclopropylidenecarbonyl.This can be used as a test for determining the mutual arrangement of the carbonyl group in the spiro fragment in the adducts of dichloroketene and methylenecyclopropanes.
Kinetics of reactions of chlorinated vinyl radicals CH2CCl and C2Cl3 with molecular oxygen
Russell,Seetula,Gutman,Senkan
, p. 1934 - 1938 (2007/10/02)
The kinetics of the reactions of CH2CCl and C2Cl3 radicals with O2 have been studied in a tubular flow reactor coupled to a photoionization mass spectrometer in the temperature range 298-648 K. Radicals were produced by the homogeneous photolysis of a suitable precursor using an excimer laser. The observed or indicated reaction mechanisms as well as the rate constants, which were measured as a function of density and temperature, suggest that both of these reactions proceed via the formation of a short-lived bound RO2 intermediate that can either decompose back to the original reactants or form new oxygen-containing products following internal rearrangement of the adduct.
ASYMMETRIC INDUCTION IN THE CYCLOADDITION REACTION OF DICHLOROKETENE WITH CHIRAL ENOL ETHERS. A VERSATILE APPROACH TO OPTICALLY ACTIVE CYCLOPENTENONE DERIVATIVES.
Greene, Andrew E.,Charbonnier, Florence
, p. 5525 - 5528 (2007/10/02)
Significant asymmetric induction has been observed in the cycloaddition reaction of dichloroketene with chiral enol ethers.The resultant diastereomeric cyclobutanones have been converted to synthetically useful α-chlorocyclopentenones in optically active form.
HEI PHOTOELECTRON SPECTRA OF UNSTABLE MOLECULES: MONO- AND DIHALOGENOKETENES
Colbourne, David,Westwood, Nicholas P. C.
, p. 2049 - 2054 (2007/10/02)
HeI Photoelectron spectra are reported for the mono- and di-chloro-and-bromo-ketenes (XHC=C=O and X2C=C=O, X=Cl,Br) generated in high yield as unstable molecules from thermolysis of acid halides.The spectra are discussed and assigned by reference to the parent ketene molecule, orbital trends, and comparison with theoretical calculations.
