Intermolecular Interactions in 8-Aza-D-Homogonane Crystals and their Manifestation in the IR Spectra

Crystalline modifications of 8-aza-D-homogon-1,3,5(10),13-tetraen-12,17a-dione have been investigated by IR spectroscopy and x-ray structural analysis. It is shown that this compound crystallizes from solutions of chloroform with hexane in the form of a solvate comprised of chelate hydrogen bonds between the hydrogen atom of the chloroform molecule and the oxygen atoms of the carbonyl groups of the 8-azasteroid molecule. A relation between the changes in the characteristic absorption bands of the CH₂-, C=O-, and I=C groups and the structure of the crystalline modifications has been established.     

Integral Newton-Type Polynomials with Continual Nodes

We construct an integral Newton-type interpolation polynomial with a continual set of nodes. This interpolant is unique and preserves an operator polynomial of the corresponding degree.     

Functionalization of 8-aza-D-homogona-1,3,5(10),13-tetraene-12,17a-diones at positions 11 and 17 under the conditions of the claisen ester condensation. Synthesis and properties of 11- and 17-acylsubstituted 8-aza-d-homogonanes

It was shown that 8-aza-D-homogona-1, 3, 5(10),13-tetraene-12,17a-diones enter into the Claisen ester condensation at the C(₍₁₁₎H₂ and C₁₇H₂ groups, whereas the C₍₁₅₎H₂ group is inert under the investigated conditions. It was established that the direction of the reaction is determined by the structure of the 8-azasteroid substrate. In the presence of a bulky gem-dimethyl group at position 16 the reaction takes place exclusively at the C₁₁H₂ group, while in the absence of this restriction the C₍₁₁₎H₂ and C₍₁₇₎H₂ groups are equivalent. The data from IR, UV, and¹H and¹³C NMR spectroscopy of the initial and synthesized derivatives of 3-aza-D-homogonanes are presented and discussed.Institute of Bioorganic Chemistry, Academy of Sciences of Belarus', Minsk. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 959–965, July, 1995. Original article submitted May 6, 1995.     

Investigation of the regio-and stereoselectivity of the annelation reaction of cyclic schiff base with structurally asymmetrical β,β′-triketones. Synthesis and properties of 17-acetoxy-8-aza-D-homogona-12,17a-diones

Annelation ([2+4]-cyclocondensation) of 3,4-dihydroisoquinolines and 2-acetyl-4-acetoxycyclohexane-1,3-dione gives 17-acetoxy-8-aza-D-homogona-12,17a-diones as a mixture of the C(9),C(17)-stereoisomers with the (9R,17S: 9S,17R) racemic pair predominating.Institute of Bioorganic Chemistry, National Academy of Sciences of the Belorussian Republic, Minsk 220141; e-mail: prostan@ns.iboch.ac.by. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1092–1099, August, 2000.     

Passage to a synchronous reference system and an estimate of the components of the metric tensor on the boundary of R and T regions

Conditions imposed on transformations leading to a synchronous reference system are obtained. The spherically symmetric case is considered in detail. It is shown that the known synchronous metrics (for example, the Lemaitre and Tolman metrics) can be obtained as a special case of those presented in the paper. The method developed in the work is applied to obtain estimates of the components e^gu and e^gl of the metric tensor in a rigid reference system on approach to the boundary of R and T regions from the side of an R region in the case where matter is present.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 53–56, 1978.     

Angularly alkylated 8-aza-D-homogonanes

We have established that cyclic azomethines (1-alkyl-substituted 3,4-dihydroisoquinolines) enter into the annelation reaction with cyclic -triketones (2-acyl-1,3-cyclohexanediones) with formation of C-9 angularly alkylated 8-aza-D-homogonanes. We have shown that the reaction of asymmetric -triketones (2-acetyl-5,5-dimethyl-4-methoxycarbonyl-1,3-cyclohexanedione) is accomplished regioselectively, leading to the 17-methoxycarbonylated 8-aza-D-homogonane derivative, existing in solutions in the form of a mixture of stereiosomers with respect to C-17 (due to keto-enol tautomerism) and in crystals in the form of a single stereoisomer. The structure of the 8-azo-D-homogonanes has been proven by UV, IR, and PMR spectra.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 86–93, January, 1993.     

Reaction of 2-chloroacetyl-1,3-cyclohexanediones with cyclic Schiffs bases. A new approach to 8-aza-D-homogone-1,3,5(10),9(11),13-pentaene-12,17A-dione

We have studied the reaction of 3,4-dihydroisoquinolines and their hydrochlorides with 2-chloroacetyl-1,3-cyclohexanediones. We have shown that the reaction in alcoholic solutions of HCl leads to annelation of the cyclic Schiff's bases by -triketones with formation of ABCD-tetracyclic 8-aza-D-homogonanium chlorides, treatment of which with bases gives 9,11-dehydro derivatives of 8-aza-D-homogona-1,3,5(10),13-tetraene-12,17a-diones.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1368–1373, October, 1993.     

[3+3] Cyclocondensation of 1-alkyl-substituted 3,4-dihydroisoquinolines with 2-aminomethylenecycloalkane-1,3-diones or aminomethylene malonates: A novel annelation reaction in the series of cyclic Schiff's bases

A new approach to the construction of polycyclic skeletons of fused azines with nitrogen at the bridgehead based on a novel reaction of cyclic Schiff's bases (1-alkyl-substituted 3,4-dihydroisoquinolines) with α-aminomethylenecarbonyl compounds (2-aminomethylene-cyclohexane-1,3-diones or aminomethylenemalonic ester) was developed. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1358–1360, July, 1997.     

Antioxidative Stabilization of Polyethylene Glycol in Aqueous Solutions with Herb Phenols

The effect of compounds extracted from herbs on oxidation of polyethylene glycol in aqueous solutiuons was studied.     

Interaction of Cyclic Schiff's Bases with 2-Methylthiopyrimidine-4,6-dione Enol Acetate. Synthesis of 5-(2-Acetyl-6,7-dimethoxy-1,2,3,4-tetrahydro-1-isoquinolyl)-6-hydroxy-2-methylthio-1,4-dihydro-4-pyrimidinones

5-(2-Acetyl-1,2,3,4-tetrahydro-1-isoquinolyl)-6-hydroxy-2-methylthio-1,4-dihydro-4-pyrimidinones have been obtained by the interaction of 3,4-dihydroisoquinolines with 2-methylthio-4-oxo-1,4-dihydro-6-pyrimidinyl acetate. It was shown that N,O-methyl derivatives are formed in interaction of the obtained products with diazomethane.