Synthesis of Some Spirochroman‐4‐ones by Regioselective [4 + 2] Cycloaddition Reactions.

Abstract

Reactions. -The synthesis of title compounds (III) is accomplished by cycloaddition of dihydroisoquinolinium salts (I) and chromanones (II). Independent of the electronic effects of the substituents in the aryl residue of (II) the reaction is regio-and stereoselective. The acid-catalyzed isomerization of strained spiro compounds (III) affords the more stable pyrrole derivative (IV). -(ASKRI, M.; RAMMAH*, M.; MONNIER-JOBE, K.; CIAMALA, K.; KNORR, M.; STROHMANN, C.; Lett.

Synthesis of Isoxazole and 1,2,3-Triazole Isoindole Derivatives via Silver- and Copper-Catalyzed 1,3-Dipolar Cycloaddition Reaction

“…One of the research activities of our laboratory in the domain of heterocyclic chemistry deals with the 1,3-dipolar cycloaddition of nitrile oxides and azides as dipoles across the double or triple bonds of dipolarophiles [1][2][3]. A very recent example is the 1,3-dipolar cycloaddition of aryl nitrile oxides to the allyl group of ethyl 1-allyl-2-benzyl-3-oxo-2,3-dihydro-1H-isoindole-1-carboxylate providing a series of isoxazolines [4].…”

Synthesis of 1,2,3-Triazole 5-Chloroisatin Derivatives via Copper-Catalyzed 1,3-Dipolar Cycloaddition Reactions

“…One of the research activities of our laboratory in the domain of heterocyclic chemistry deals with the 1,3-dipolar cycloaddition of nitrile oxides and azides as dipoles across the double or triple bonds of dipolarophiles [1][2][3]. A very recent example is the 1,3-dipolar cycloaddition of nitrile oxides to the allyl group of 1-allyl-5-chloro-indole-2,3-dione providing a series of isoxazolines [4].…”