Reactions of dicarbonyl compounds with dimethyl .beta.-ketoglutarate. 6. Revision of the structure of the reaction product of cyclohexane-1,3-dione and dimethyl .beta.-ketoglutarate and conversion to 4-substituted 5,6,7,8-tetrahydro-5-oxo-2-quinolones

Abstract

In our first report concerning the reactions of 1,2-and 1,3-dicarbonyl compounds with dimethyl /3-ketoglutarate (1), we proposed structure 3a for the product obtained from reaction of cyclohexane-1,3-dione (2a) with 1 at pH 6.8. This structure has now been revised to methyl 5,6,7,8-tetrahydro-5-oxocoumarin-4-yl acetate (4a) based on UV and 13C NMR data. In addition, the tetrahydro-5-oxocoumarin derivatives 4a and 4b were converted to the corresponding 5,6,7,8-tetrahydro-5-oxo-2-quinolones 10a, 11a, 10b, and lib, respectively, by reaction with N-benzylamine or ammonia. The 13C NMR spectra of these 2-quinolones are presented and discussed.During studies on the reaction of dicarbonyl com-poundsli2a"c with dimethyl /3-ketoglutarate (1) we reported, in preliminary form,3 that stirring cyclohexane-1,3-dione (2a) with 1 at pH 6.8 provided the lactone 3a. We would now like to revise the structure of this reaction product to the a-pyrone derivative, methyl 5,6,7,8-tetrahydro-5-oxocoumarin-4-yl acetate (4a),4 based on analogies between the UV and 13C NMR spectra of 4a with the spectra of 4-methyl-5,6,7,8-tet-

Utilisation of 1,3‐Dicarbonyl Derivatives in Multicomponent Reactions

“…The aim of this microreview is to present an overview of the high synthetic potential of MCRs involving the specific reactivity of easily accessible 1,3‐dicarbonyl derivatives29 and to stress their more recent utilisation for the development of new useful methodologies valuable for the selective construction of highly functionalised small organic molecules of high synthetic and biological value. This presentation focuses only on MCRs involving at least three different substrates, with no discussion being made of transformations dealing with the utilisation of a twofold excess of 1,3‐dicarbonyls with another substrate 30−35…”

Uses of ethyl benzoyl acetate for the synthesis of thiophene, pyran, and pyridine derivatives with antitumor activities

“…1,3‐dicarbonyl compounds and their applications in MCRs producing biologically active products with highly functionalized small organic molecules with biological interest [ 29 ] were received many attentions in recent years. These reactions involving the mixing of three substrates together or sometimes the use of twofold of substrate to produce heterocyclic target molecules with diverse biological interest [ 30–35 ] . In the present work, we report the uses of the N ‐(aryl)propanamide derivatives 3a,b as β‐diketone for the synthesis of thiophene, pyran, and pyridine derivatives followed by their antitumor evaluations.…”