Reactions of Ketene Acetals. IV. A New Synthesis of α-Pyrones. III

1975 ◽  
Vol 53 (2) ◽  
pp. 201-208 ◽  
Author(s):  
Alain Bélanger ◽  
Paul Brassard
Keyword(s):  
New Synthesis ◽  
One Step ◽  
Ketene Acetals ◽  
Mechanism Of The Reaction

A simple one-step synthesis of α-pyrones and 3-chloro-α-pyrones from β-functionalized α, β-enones and ketene acetals has been devised. The method has also been adapted to the preparation of some 4-methoxy-α-pyrones. Finally the mechanism of the reaction has been investigated.

Chemistry of kojic acid: One-step syntheses of benzothiazoles and other fused heterocycles from kojic acid derivatives

1983 ◽  
Vol 36 (11) ◽  
pp. 2307 ◽  
Author(s):  
T Teitei
Keyword(s):  
Kojic Acid ◽  
Benzyl Ether ◽  
Pyridine Derivatives ◽  
Reaction Products ◽  
Fused Heterocycles ◽  
One Step ◽  
Mechanism Of The Reaction

The reactions of the benzyl ether (1b) of kojic acid (la) and its chloromethyl derivative (1c) were investigated as new routes to fused heterocyclic systems. The chloromethyl compound proved the more versatile intermediate yielding benzothiazoles with thiourea and pyrido[l,2-a]benzimidazoles (11) and pyrido[1,2-alindole (12b) with pyridine derivatives. A number of methylated products of the benzothiazole were prepared in order to establish the structures of the reaction products and a possible mechanism of the reaction is discussed.

Ruthenium-Catalyzed Synthesis of Pyrrolo[1,2-a]quinoxaline Derivatives from 1-(2-Aminophenyl)pyrroles and Sulfoxonium Ylides

Synlett ◽  
2020 ◽  
Vol 31 (12) ◽  
pp. 1205-1210 ◽  
Author(s):  
Guo-Sheng Huang ◽  
Xin-Feng Cui ◽  
Fang-Peng Hu ◽  
Xiao-Qiang Zhou ◽  
Zhen-Zhen Zhan
Keyword(s):  
Reaction Time ◽  
Functional Group ◽  
Reaction Pathway ◽  
Ambient Conditions ◽  
Step Method ◽  
Short Reaction Time ◽  
Quinoxaline Derivatives ◽  
One Step ◽  
Preliminary Study ◽  
Mechanism Of The Reaction

A ruthenium-catalyzed [5+1] annulation of 1-(2-aminophenyl)pyrroles with α-carbonyl sulfoxonium ylides is reported. This reaction provides a one-step method for synthesizing pyrrolo[1,2-a]quinoxaline derivatives under ambient conditions. The system proceeds with a short reaction time and a high functional-group tolerance. Notably, this divergent protocol tolerates β-keto sulfoxonium ylides and can be applied to α-ester sulfoxonium ylides. A preliminary study was made of the mechanism of the reaction, and a reaction pathway is proposed.

Ketene Acetals. I. A New Synthesis of Ketene Acetals and Ortho Esters1

1964 ◽  
Vol 29 (9) ◽  
pp. 2773-2775 ◽  
Author(s):  
William C. Kuryla ◽  
Donald G. Leis
Keyword(s):  
New Synthesis ◽  
Ketene Acetals

scholarly journals Scandium and Dimethylaminopyridine Catalyzed Dehydrative Coupling of Secondary Benzylic and Primary Alcohols to Synthesize Unsymmetrical Ethers

2020 ◽  
Author(s):  
Julia Duncan ◽  
Lun Li ◽  
Vahid Mohammadrezaei ◽  
Laina Geary
Keyword(s):  
Spectroscopic Data ◽  
Supplementary Information ◽  
Primary Alcohols ◽  
Benzylic Alcohols ◽  
Benzylic Alcohol ◽  
Catalytic Condensation ◽  
Rapid Formation ◽  
One Step ◽  
Insight Into ◽  
Mechanism Of The Reaction

We developed a direct catalytic condensation of benzylic alcohols and primary alcohols to synthesize unsymmetrical ethers in one step, catalyzed by scandium triflate and p-dimethylaminopyridine (DMAP). Preliminary experiments give some insight into the mechanism of the reaction, though suggest that the process is quite complex. We suspect the rapid formation of a dimer from a secondary benzylic alcohol via a carbocation intermediate precedes unsymmetrical ether formation. Full experimental details and spectroscopic data are provided as supplementary information.

Reactions of Ketene Acetals. III. A New Synthesis of α-Pyrones. II

1975 ◽  
Vol 53 (2) ◽  
pp. 195-200 ◽  
Author(s):  
Alain Bélanger ◽  
Paul Brassard
Keyword(s):  
Reaction Conditions ◽  
Unsaturated Aldehydes ◽  
New Synthesis ◽  
Aldehydes And Ketones ◽  
Ketene Acetals ◽  
By Products

The cycloaddition of chloroketene acetals to α, β-unsaturated aldehydes and ketones gives the corresponding 2,2-dialkoxy-3-chloro-3,4-dihydro-1,2-pyrans. Treatment of these compounds with alkoxides in dimethylsulfoxide or dimethylformamide yields α-pyrones directly. Some intermediates and by-products have been identified and the reaction conditions have been studied.

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