Photoinduced N-β-hydroxyalkylation of tropan derivatives

The photooxidation of tropan derivatives by ketones was studied; the targeting of the reaction to the N-CH₃ group with the formation of N-alkylation products and bis-tropan derivatives was demonstrated. The presence of two diastereomers in salts of N-alkyl derivatives of tropan was detected by PMR spectroscopy. An alternative method of synthesis of difficult-to-obtain amino alcohols was proposed.Scientific-Research Institute of Pharmacology, Russian Academy of Medical Sciences, Moscow 125315. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 179–183, February, 1995. Original article submitted September 5, 1994.     

Some derivatives of α-pyrone-3-carboxylic acid and its homologs

Saponification of the appropriate 3-carbethoxy-α-pyrones gives α-pyrone-3-carboxylic acid and its homologs, further converted via their acid chlorides to the substituted amides of the acids.     

Photochemical oxidation of 1,2,2,6,6-pentamethyl-4-piperidol by ketones

Chemistry of Heterocyclic Compounds -     

Pathways of photooxidation of 1,2,2,6,6-pentamethyl-4-piperidol by ketones

The photochemical oxidation of 1,2,2,6,6-pentamethyl-4-piperidol by ketones occurs exclusively at the methylamino group and, in the case of photolytically stable ketones, may lead to products of dimerization of the aminoalkyl radicals and recombination of the aminoalkyl and ketyl radicals and to a product of N-demethylation of the starting amino alcohol. When ketones that are unstable with respect to irradiation are used, photooxidation competes to a considerable extent with photodecomposition of such ketones. Spatial proximity of the aryl and -methyl groups are observed for the products of reductive addition of the ketones on the basis of the PMR spectra.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1657–1661, December, 1982.     

Proton magnetic resonance study of the configurations of severalΒ-substituted vinylcarbonyl compounds

PMR spectra of several -substituted vinylcarbonyl compounds were studied. Analysis of the spin-spin interaction constants and the chemical shifts leads to the conclusion that the molecules of methyl cis- and trans--chlorovinyl ketone, methylmalondialdehyde, and malondialdehyde exist in a cissoidal conformation. The molecule of cis--chloroacrolein has a transoidal conformation, and a rotation around the C-C bond takes place in trans--chloroacrolein.The results of the experiments are compared with calculated chemical shifts, which are determined by the effect of diamagnetic anisotropy and electrical charges of the C=C, C=O, and C-Cl bonds.