Synthesis and properties of hydrocarbons of mixed structure and high molecular weight

Russian Chemical Bulletin -     

The spatial structure of the isomeric dimethyl esters of 4-hydroxypiperidine-2, 6-dicarboxylic acid

Three isomeric dimethyl esters of 4-hydroxypiperidine-2, 6-dicarboxylic acid have been isolated. The spatial structures of all three isomeric esters and of the acids corresponding to them have been established on the basis of NMR spectra. It has been shown that while the isomers I and II exist in the form of only one conformation each, isomer III in neutral and acid media apparently consists of an equilibrium mixture of two (or more) conformers. The information obtained on the spatial structure of the isomeric esters shows that the cyclization of these compounds with benzylamine and p-nitrobenzaldehyde takes place with the inversion of the piperidine ring.     

Synthesis and configuration of diastereomeric 1-(β-dimethylaminoethyl)-2,5-dimethyl-4-plperidols

Diastereomeric 1-(-dimethylaminoethyl)-2,5-dimethyl-4-piperidols were synthesized and their configurations were studied. The spatial orientation of the substituents in the , , and isomers of 2,5-dimethyl-4-piperidol was established, and the stereochemistry of the reduction of 2,5-dimethyl-4-piperidone with sodium in alcohol, with lithium aluminum hydride, and by catalysis on Raney nickel was studied by PMR spectroscopy. A series of transformations at the nitrogen atom of the piperidine ring do not change the configuration of 2,5-dimethyl-4-piperidols, but the stereochemistry of the reduction of the keto group in 2,5-dimethyl-4-piperidones with lithium aluminum hydride depends markedly on the character of the substituent attached to the piperidine nitrogen.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1374–1378, October, 1973.     

The synthesis of 7-hydroxy-3, 9-diazabicyclo[3.3.1]nonane

7-Hydroxy-3, 9-diazabicyclo[3.3.1]nonane is synthesized, starting from the dimethyl ester of the 4-hydroxypiperidine-2, 6-dicarboxylic acid, by preparing the N-benzyl derivative and cyclizing the latter with benzylamine to the benzylimide of the 1-benzyl-4-hydroxypiperidine-2, 6-dicarboxylic acid. On reduction of the given imide with lithium aluminum hydride and catalytic hydrogenolysis of the benzyl groups, the final 7-hydroxy-3,9-diazabicyclo[3.3.1]nonane is obtained, the three-dimensional structure of which (chair-chair type) is proved by comparison of its methyl derivative with a known compound of demonstrated three-dimensional structure.     

Spatial structure of some derivatives of piperidin-4-ol

Conclusions The spatial structures of a number of piperidine-4-olderivatives having substituents in the ring such as methyl, methoxy- and ethoxycarbonyl, and phenyl groups, have been determined by means of their PMR spectra.Ordzhonikidze Scientific-Research Institute of Pharmaceutical Chemistry. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 591–598, September–October, 1970.     

Spatial structure of some derivatives of piperidin-4-ol

Chemistry of Natural Compounds - The spatial structures of a number of piperidine-4-olderivatives having substituents in the ring such as methyl, methoxy- and ethoxycarbonyl, and phenyl groups,...     

Synthesis and transformations of 6,6,7,7-tetramethyl-2-quinuclidone

6,6,7,7-Tetramethyl-2-quinuclidone was synthesized, and its differences from the usual amides were shown. It enters into three types of chemical reactions: 1) the N-CO bond is broken under the influence of protic nucleophilic agents (water, alcohols, amines, hydroxylamine, and hydrazines), and nucleophilic agents are acylated by the (2,2,6,6-tetramethyl-4-piperidyl)-acetic acid residue; 2) the N-C(CH₃)₂ bond is broken by reaction with nucleophilic agents in aprotic media (phenyllithium in ether, PCl₅ in benzene, acetone cyanohydrin, and LiAlH₄ in ether) to form 4-substituted 6,6-dimethyl-2-piperidones; 3) reactions with the preservation of the quinuclidine ring occur on treatment with electrophilic reagents (hydrogen chloride and methyl iodide) in aprotic solvents and during reduction.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 378–384, March, 1971.     

Several transformations of 3-benzyl-9-carbethoxymethyl-3,9-diazabicyclo[3.3.1]nonane

The transformations of 3-benzyl-9-carbethoxymethyl-3,9-diazabicyclo[3.3.1]nonane (I) were studied. The dichloride of 9-(-chloroethyl)-3,9-diazabicyclo[3.3.1]nonane, which is readily cyclized in the basic form to 3,9-diazatricyclo[3.3.1.2^3,9]undecane (V), was synthesized by reduction of I with LiAlH₄ and debenzylation with subsequent replacement of the hydroxy group, in the alcohol formed, by chlorine. An unusual cleavage of the carboxymethyl residue to form the nitrogen-unsubstituted dichloride of 3,9-diazabicyclo[3.3.1]nonane (XI) occurs on treatment with thionyl chloride of the acid obtained by saponification and debenzylation of I.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1372–1375, October, 1970.     

Investigation of the reaction products of triacetonamine and ethyl cyanoacetate under knoevenagel reaction conditions

Reaction of triacetonamine with ethyl cyanoacetate and ammonium acetate gives, in addition to the normal Knoevenagel reaction product (2,2,6,6-tetramethyl-4-ethoxycarbonylcyanomethylenepiperidine), its conversion product 3-cyano-4-(,-dimethylvinyl)-6,6-dimethyl-³-dehydro-2-piperidone. Acid hydrolysis of the latter gives a dihydro--pyrone derivative. The mechanism of the formation of the new compounds is discussed, and their structures are proved by their NMR and mass spectra.Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 6, No. 5, pp. 642–646, May, 1970.