Transformation of quaternary 5-benzyl-2-(2-ethoxy-2-oxoethyl)-and-2-cyanomethyl-2-methyl-2,3,4,4a,5,9b-hexahydro-1H-pyrido[4,3-b]indol-2-ium salts into 1,2,3,4,7,12-hexahydroazonino[4,5-b]indole derivatives

γ-Carbolines and their hydrogenated derivatives 3.* Hydrogenated derivatives of γ-carbolines: chemical and biological poperties (Review)

“…The quaternized tetrahydro-γ-carboline derivatives 44, containing an active methylene group at the N(2) atom, react with acetylenedicarboxylic ester in the presence of alkali under the conditions of phase-transfer catalysis to form hexahydroazocino [4,5-b]indoles 45 with moderate yields [70]. The reaction apparently takes place through the formation of the N-ylides 46, the carbanionic center of which attacks the activated bond with the formation of the 1,4-zwitterion 47, and this undergoes a [1,4]-sigmatropic shift with the formation of the skeleton of azocino[4,5-b]indoles 45 [71].…”

Unexpected course for the reaction of 1-di(ethoxycarbonyl)methyl-1-methyl-4-phenyl-1,2,3,6-tetrahydropyridinium bromide with dimethyl acetylenedicarb-oxylate in the presence of triethylamine

“…IR spectrum, ν, cm -1 : 1731 sh, 1727 (C=O), 1631 (C=C). 1 H NMR spectrum, δ, ppm (J, Hz): 1.20 (3H, t, J = 7.6, OCH 2 CH 3 ); 1.30 (3H, t, J = 7.6, OCH 2 …”

“…The electrophilic acetylene dicarboxylate ester 2 adds to the initially formed N-ylide and the 1,4-zwitterion formed evidently undergoes a 1→3 acyl shift of one of the ethoxycarbonyl groups to the carbanion center. This shift leads to a new ylide which can undergo a [3,2]-sigmatropic rearrangement with recyclization of the piperidine ring to a pyrrolidine.…”

“…In this work we have studied the reaction of 1-di(ethoxycarbonyl)methyl-1-methyl-4-phenyl-1,2,3,6-tetrahydropyridinium bromide (1) with dimethyl acetylenedicarboxylate (2) in the presence of triethylamine under analogous conditions (20ºC, 32 h). However, in place of the expected azonine derivative, column chromatography of the reaction mixture unexpectedly gave a 25% yield of the substituted pyrrolidine 3, the 2-ethenyl group of which contains three alkoxycarbonyl substituents.…”

“…

Using acetylenedicarboxylic ester in the presence of base it has been possible to show for the first time that reaction of 2,3-dihydro-1H-indeno[2,1-c]pyridinium [1] and 1,2,3,4-tetrahydro-γ-carbolinium [2] quaternary salts to tetrahydroindenoazonines and hexahydroazoninoindoles respectively can occur with expansion of the six membered ∆ 3 -piperidine ring (with an alkoxycarbonylmethyl substituent on the nitrogen atom) to a nine membered ring [1,2]. In this work we have studied the reaction of 1-di(ethoxycarbonyl)methyl-1-methyl-4-phenyl-1,2,3,6-tetrahydropyridinium bromide (1) with dimethyl acetylenedicarboxylate (2) in the presence of triethylamine under analogous conditions (20ºC, 32 h).

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