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Methyl 2-acetylamino-5-[2-(6-methylpyridin-3-yl)vinyl]benzoate reacted with phenacyl bromide to produce quaternary 1-(2-aryl-2-oxoethyl)-2-methyl-5-(4-acetylamino-3-methoxycarbonyl)pyridinium bromides. 1,3-Dipolar cycloaddition of the latter to methyl propynoate and dimethyl but-2-ynedioate gave the corresponding indolizine derivatives containing an anthranilic acid ester moiety. Reactions of acetylenes with N-phenacylpyridinium salts obtained from a diterpene alkaloid derivative, 2-(pyridin-3-yl)vinyl-substituted lappaconitine afforded analogous compounds in which the indolizine fragment is conjugated to the aromatic ring of the alkaloid. 1,3-Dipolar cycloaddition of 1-(2-aryl-2-oxoethyl)-2-methyl-5-(4-acetylamino-3-methoxycarbonyl) pyridinium bromides with methyl propynoate was regioselective. [ABSTRACT FROM AUTHOR]

Nitro-derivatives of lappaconitine were synthesized for the first time by nitration of the alkaloid and its 5′-bromo-derivative using a trifluoroacetic acid and potassium nitrate nitrating mixture. Reduction of the nitro-derivatives by Sn(II) chloride in HCl produced the corresponding amino-derivatives of N-deacetyllappaconitine. [ABSTRACT FROM AUTHOR]

New N-acylates of the norditerpenoid alkaloid N-deacetyllappaconitine that were modified in the aromatic ring and are interesting as potential pharmacologically valuable compounds were prepared. [ABSTRACT FROM AUTHOR]

Bromination of endo-ethenotetrahydrothebaine derivatives having a pyrrolidine ring fused at the C7-C8 bond, namely 1′-substituted 4,5α-epoxy-6α,14-etheno-3,6-dimethoxy-17-methyl-2′,5′,7β,8β-tetrahydro-1′ H-14α-pyrrolo[3′,4′:7,8]morphinan-2′,5′-diones, 1′-aryl-4,5α-epoxy-6α,14-etheno-3,6-dimethoxy-17-methyl-2′,5′,7β,8β-tetrahydro-1′ H-14α-pyrrolo[3′,4′:7,8]morphinans, and 4,5α-epoxy-6α,14-etheno-2′α-hydroxy-3,6-dimethoxy-17-methyl-1′-phenyl-2′,5′,7β,8β-tetrahydro-1′ H-14α-pyrrolo[3′,4′:7,8]morpphinan-5′-one, with molecular bromine in formic acid smoothly afforded the corresponding 1-bromo derivatives. Iodination of 4,5α-epoxy-6α,14-etheno-3,6-dimethoxy-17-methyl-1′-phenyl-2′,5′,7β,8β-tetrahydro-1′ H-14α-pyrrolo[3′,4′:7,8]-4,5α-epoxy-6α,14-etheno-3,6-dimethoxy-17-methyl-1′-phenyl-2′,5′,7β,8β-tetrahydro-1′ H-14α-pyrrolo[3′,4′:7,8]-morphinan-2′,5′-dione with iodine(I) chloride gave 4,5α-epoxy-6α,14-etheno-1-iodo-3,6-dimethoxy-17-methyl-1′-phenyl-2′,5′,7β,8β-tetrahydro-1′ H-14α-pyrrolo[3′,4′:7,8]morphinan-2′,5′-dione. The resulting 1-halo derivatives were brought into the Heck reaction with acrylic acid esters to obtain 1-[( E)-2-(alkoxycarbonyl)ethenyl]-substituted compounds. Demethylation of the 6-methoxy group in 1-bromo- endo-ethenotetrahydrothebaines was accomplished using boron(III) bromide in chloroform. [ABSTRACT FROM AUTHOR]

Elect rocatalytic reduction of the alkaloids anabasine and nicotine was investigated. 1-α,β' -Dipiperidyl and hexahydronicotine were prepared. The reactions of anabasine and the hydrogenated alkaloids with dicarboxylic acid anhydrides were studied. [ABSTRACT FROM AUTHOR]

[1+2]Cycloaddition to thebaine alcaloid under catalysis by copper triflate of carbene generated from CH2N2 occurred stereoselectively affording 6β,7β-methylene-6,7-dihydrothebaine. The simultaneously proceeding 8β,14β-cyclopropanation and nitrogen quaternization furnished N,N-dimethyl-N-nor-8β,14β-methylene-8,14-dihydrothebaine triflate whose structure was established by X-ray diffraction analysis. The possibility of preparation of 14β-hydroxy-6β,7β-methylene-8α-substituted dihydrocodeine derivatives was demonstrated. [ABSTRACT FROM AUTHOR]

Quaternary salts of the alkaloid glaucine with alkyl iodides have been obtained. The crystal and molecular structure of the methyl iodide salt was studied by x-ray structure analysis. The synthesized compounds were tested for antimicrobial activity with respect to both Gram-positive ( Staphylococcus aureus, Bacillus subtilis) and Gram-negative ( Escherichia coli) bacteria. [ABSTRACT FROM AUTHOR]