Synthesis and three-dimensional structures of geometrical isomers of some 4-substitute d 1,2,5-trimethyl-4-acetoxy- and 1,2,5-trimethyl-4-benzoxypiperidines

Stereoisomers of the corresponding 4-substituted 1,2,5-trimethyl-4-acetoxy- and 1,2,5-trimethyl-4-benzoxypiperidines were obtained by acylation of the geometrical isomers of 1,2, 5-trimethyl-4-piperidol and its 4-ethynyl, 4-ethyl, and 4-phenyl-substituted derivatives. The preferred conformations of the investigated esters were elucidated by means of the PMR and IR spectra.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No.1, pp. 50–55, January, 1973.     

A metallo-capped polyrotaxane containing calix[4]arenes and cyclodextrins and its highly selective binding for Ca2+

A water-soluble nanometer-scale metallocapped polyrotaxane has been prepared by the inclusion complexation of azo-calixarenes with metallo-bridged bis(beta-CD)s, displaying highly selective binding for Ca(2+).     

Synthesis of acetyltrialkylpyrroles from 2, 4-pentanediones

The condensation of isonitrosoacetylacetone with 3-alkyl-2,4-pentanediones and reduction with zinc in acetic acid gives-acetyltrialkylpyrroles. The analogous condensation of 3-alkyl-3-nitroso-2,4-pentanediones with acetylacetone leads to-acetyltrialkylpyrroles, and condensation with acetoacetic ester leads to-ethoxycarbonyltrialkylpyrroles. When the- and-acetyltrialkylpyrroles undergo salt formation, the oxygen of the carbonyl group is protonated.     

Polarographic investigation of the mobility of halogen atoms in halogen-substituted components of nucleic acids

In order to establish quantitatively the reducibility of halogen-substituted components of nucleic acids, the half-wave potentials (E_1/2) of their electrochemical reduction have been determined. The electrochemical reduction of all compounds takes place in the interval from –0.5 to –1.8 V and consists in the splitting off of the halogen atom (iodine, bromine) from the given molecule. The iodine derivatives are reduced much more readily (500–800 mV) than the bromine derivatives.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1404–1408, October, 1992     

Addition of amines to ethyl α-fluoroacrylate and phenyl α-fluorovinyl ketone

Conclusions The reaction of diethylamine, piperidine, ethylenimine, and cyclohexylamine with ethyl-fluoroacrylate, and also of ethylenimine with phenyl-fluorovinyl ketone, leads to the addition of the amines to the-fluorovinyl group with the formation of-fluoro--aminopropionic acid derivatives.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicneskaya, No. 10, pp. 2362–2363, October, 1975.