Anomalous acid-catalyzed reactions of cyclobutanones

1969 ◽  
Vol 47 (15) ◽  
pp. 2797-2802 ◽  
Author(s):  
Edward Lee-Ruff ◽  
Nicholas J. Turro ◽  
P. Amice ◽  
J. M. Conia
Keyword(s):  
Carboxylic Acids ◽  
Polyphosphoric Acid ◽  
Ring Cleavage ◽  
Phosphorous Pentoxide ◽  
Acid Catalyzed ◽  
Catalyzed Reactions

The reactions of 2(2-isopropanol)cyclobutanones with phosphorous pentoxide lead to ring opened carboxylic acids. Reaction of 2-isopropylidenecyclobutanones with polyphosphoric acid (PPA) gives ring cleavage rearrangement products. The mechanisms of these reactions are discussed in the light of the observed different reactions of the corresponding cyclopentanones.

Acid-catalyzed reactions of ortho-substituted benzohydroxamic acids in polyphosphoric acid (PPA)

1986 ◽  
Vol 51 (23) ◽  
pp. 4458-4460 ◽  
Author(s):  
P. N. Chhaya ◽  
M. M. Nimbalkar ◽  
B. D. Hosangadi
Keyword(s):  
Polyphosphoric Acid ◽  
Acid Catalyzed ◽  
Catalyzed Reactions

Article

1999 ◽  
Vol 77 (5-6) ◽  
pp. 744-751
Author(s):  
Robert Eliason
Keyword(s):  
Acetic Acid ◽  
Carboxylic Acids ◽  
Hydrogen Isotope ◽  
Isotope Effects ◽  
Water Concentration ◽  
Chloroacetic Acid ◽  
Water Effect ◽  
First Order ◽  
Acid Catalyzed ◽  
Catalyzed Reactions

Acid-catalyzed decomposition of diazodiphenylmethane (DDM) has been studied in DMSO containing varying amounts of water. The reaction was found to be first-order in DDM and first-order in acid. The Brønsted plot for a series of carboxylic acids is curved with the H+ point falling below the curve defined by the carboxylic acids. In near-anhydrous DMSO, kinetic hydrogen isotope effects (KIEs) are 1.7 and 1.6 for acetic acid and chloroacetic acid, respectively. The chloroacetic acid KIE increases with increasing water concentration, rising to 2.9 at 3.6 M water. As a function of [H2O], kHA for chloroacetic acid shows a sharply defined minimum occurring at 1 M water. This behavior and the water effect on KIE suggest that the carboxylic acid-catalyzed reactions in near-anhydrous DMSO do not use the ASE-2 mechanism attributed to the reaction of DDM in hydroxylic solvents. A mechanism, leading to an azoalkane, is suggested. Either directly or indirectly, this may lead to diphenylcarbene, which would account for the observed products: benzophenone, benzhydrol, and benzhydryl esters. For the H+ catalyzed decomposition of DDM in near-anhydrous DMSO, benzophenone is not found among the products, and we suggest that this reaction does not undergo a change in mechanism and continues to use the ASE-2 mechanism.Key words: decomposition mechanism, kinetics, solvent effect, reaction with carboxylic acids.

Acid-catalyzed reactions of cyclobutanones. III. Formation of substituted 2-tetralones from α-phenylcyclobutanones

1978 ◽  
Vol 56 (1) ◽  
pp. 99-103 ◽  
Author(s):  
Victor P. Abegg ◽  
Alan C. Hopkinson ◽  
Edward Lee-Ruff
Keyword(s):  
Room Temperature ◽  
Phosphorous Pentoxide ◽  
Naphthalene Derivatives ◽  
Acid Catalyzed ◽  
Catalyzed Reactions

A series of cyclobutanones 1–5 were found to rearrange to β-tetralones 6–10, respectively, in the presence of phosphorous pentoxide in benzene at room temperature. The structures of the β-tetralones were inferred by conversion of a number of these known naphthalene derivatives. Possible mechanistic pathways are discussed.

Photoinduced rearrangement of hydroxymethylisoxazolines, a route to enaminoaldehydes

1986 ◽  
Vol 51 (10) ◽  
pp. 2167-2180 ◽  
Author(s):  
Lubor Fišera ◽  
Nadezhda D. Kozhina ◽  
Peter Oravec ◽  
Hans-Joachim Timpe ◽  
Ladislav Štibrányi ◽  
...  
Keyword(s):  
Thionyl Chloride ◽  
Quantum Yields ◽  
Acid Catalyzed ◽  
Catalyzed Reactions ◽  
Photoinduced Rearrangement ◽  
Condensed Heterocycles

3-Aryl-4-R-carbamoyl-5-hydroxymethylisoxazolines (IV) were synthesized by allowing R-NH2 amines with R = H, CH3, C3H7, C6H5C2H5, and NH2 to act on 3-(X-phenyl)-4-oxo-3a,4,6,6a-tetrahydrofuro[3,4-d]isoxazoles (III) with X = H, 4-CH3, 4-OCH3, 2-OCH3, 4-Cl, 2-Cl, 4-F, 2-F, 4-Br, 4-NO2, and 3-NO2. Exposed to radiation, the substances IV give Z-2-hydroxymethylamino-2-aryl-1-formylacrylamides (V) in good yields. The 4-Cl and 4-F substituted Z-derivatives V isomerize irreversibly to the E-derivatives VI if allowed to stand in solvent; the remaining derivatives V are stable. The quantum yields of the photoreaction are from 0.012 to 0.106 in dependence on the substituent X. In all cases where the compounds IV were used for the preparation of condensed heterocycles in conditions of acid-catalyzed reactions, lactones III were preferentially formed; the action of thionyl chloride on IV results in the formation of chloromethyl derivatives VIII, which do not undergo further cyclization.

Synthetic Scope of Brønsted Acid-Catalyzed Reactions of Carbonyl Compounds and Ethyl Diazoacetate

2021 ◽  
Author(s):  
Mizzanoor Rahaman ◽  
M. Shahnawaz Ali ◽  
Khorshada Jahan ◽  
Damon Hinz ◽  
Jawad Bin Belayet ◽  
...  
Keyword(s):  
Carbonyl Compounds ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Ethyl Diazoacetate ◽  
Brönsted Acid ◽  
Acid Catalyzed ◽  
Catalyzed Reactions

Kinetic modelling of reactions for the synthesis of 2-methyl-5-ethyl pyridine

2021 ◽  
Author(s):  
Emanuele Moioli ◽  
Leo Schmid ◽  
Peter Wasserscheid ◽  
Hannsjoerg Freund
Keyword(s):  
Kinetic Modelling ◽  
Acid Catalyst ◽  
Acid Catalyzed ◽  
Catalyzed Reactions ◽  
Kinetics Of

The kinetics of the acid catalyzed reactions of acetaldehyde ammonia trimer (AAT) and paraldehyde (para) to 2-methyl-5-ethyl pyridine (MEP) in the presence of an acid catalyst were investigated systematically. A...

Sign in / Sign up

Export Citation Format

Share Document