Synthesis of steroids containing a vicinal diol group in the side chain via isoxazoline intermediates

A sequence of conversions including 1,3-dipolar cycloaddition of nitrile oxides to steroid 22-enes and modification of the isoxazolines obtained by hydroxylation to the 4′ position and splitting of the heterocycle leads to steroids with a polyfunctional open chain, 22,23-dihydroxy 24-ketones. For preliminary report see [1]. Institute of Bioorganic Chemistry, Academy of Sciences of Belarus', Minsk 220141. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 542–548, April, 1997.     

Synthesis of analogs of ecdysteroids containing an isoxaline ring in the side chain

Starting with poststerone a synthesis was performed of ecdysteroid analogs containing an isoxaline ring in the side chain. The key stages of the route to the target products were Normant reaction and the subsequent 1,3-dipolar cycloaddition of nitrile oxides to 20-hydroxy-20-vinylsteroids.     

Synthesis of 1,2,4-oxadiazole derivatives containing chlorine atoms in the side chain

1,3-Dipolar cycloaddition of the N-oxides of acetonitrile, propionitrile, and p-nitrobenzonitrile to nitrites of polychloroalkanoic and polychloroalkenoic acids gives 1,2,4-oxadiazoles containing polychloroalkyl and alkenyl substituents at the 5-position.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 402–405, March, 1993.     

GC-MS analysis of acylated derivatives of the side chain and ring regioisomers of methylenedioxymethamphetamine

The perfluoroacyl derivatives (pentafluoropropionylamides and heptafluorobutrylamides) of the primary and secondary regioisomeric amines, related to the controlled drug substance 3,4-methylenedioxymethamphetamine, are prepared and evaluated in GC-MS studies. These derivatives show excellent resolution on nonpolar stationary phases, such as RTX-1 and RTX-5, with elution order differences from those of the underivatized amines. The mass spectra for these derivatives are significantly individualized, and the resulting unique fragment ions allow for specific side-chain identification. The individualization is the result of fragmentation of the alkyl carbon-nitrogen bond, yielding hydrocarbon fragments and other unique ions. The heptafluoro butrylamides derivatives offer more fragment ions for molecular individualization among these regioisomeric substances.     

An X-ray diffraction study of terminally bromo substituted side chain polysiloxanes

Abstract

X-ray diffraction results are reported for two bromo substituted side chain liquid crystal polymers with polysiloxane backbones. Both exhibit a smectic A phase with the observed lamellar d spacings being consistent with an almost totally overlapped interdigitated structure. Below the S_A phase the biphenyl derivative gives an X-ray pattern with sharp 1, 10, and 210 reflections which can be interpreted as smectic E.     

An X-ray diffraction study of terminally bromo substituted side chain polysiloxanes

X-ray diffraction results are reported for two bromo substituted side chain liquid crystal polymers with polysiloxane backbones. Both exhibit a smectic A phase with the observed lamellar d spacings being consistent with an almost totally overlapped interdigitated structure. Below the S_A phase the biphenyl derivative gives an X-ray pattern with sharp 1, 10, and 210 reflections which can be interpreted as smectic E.     

X-ray diffraction study of a polybutadiene, side chain, mesomorphic polymer

A side chain, mesomorphic polymer has been synthesized, starting from a commercial polybutadiene main chain. A preliminary X-ray diffraction study shows the influence of the degree of substitution and the spacer length on the interdigited S_A layer thickness, particularly for strongly polar alkoxycyanobiphenyl mesogens. Some hypotheses are deduced about the particular odd-even effect observed with this backbone and on the conformation of the main and side chains.     

Copolymerization of acrylonitrile. I. Copolymerization with styrene derivatives containing nitrile groups in the side chain

Acrylonitrile was copolymerized in bulk with cinnamonitrile (I), ethyl benzylidenecyanoacetate (II), and benzylidenemalononitrile (III) by radical initiation up to low conversions. The conventional scheme of copolymerization fitted all the three copolymer pairs.     

Synthesis of new liquid crystalline compounds containing a β-hydroxyketone fragment in the side chain

Liquid crystalline benzoates with a smectic meso phase were synthesized on the basis of 3-hydroxy-1-(4-hydroxyphenyl)-1-octanone by esterification of 4-alkoxybenzoic acids.Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 9, 2004, pp. 1344–1348.Original Russian Text Copyright © 2004 by Bezborodov, Kovganko.     

Proton NMR study of the conformation of ring D and its side chains in chlorophyll derivatives

The complex multiplet proton NMR pattem at 360 MHz of the propionic side chains in methyl pheophorbides and a pheofarnesin derived from bacaterioclorophyll-d is completely analyzed; the major preferred orientation in solution is found to be different from that determined by single crystal X-ray studies.     

Copolymerization of styrene. II. Emulsion copolymerization with styrene derivatives containing nitrile groups in the side chain

Copolymers of styrene with cinnamonitrile, ethyl benzylidenecyanoacetate, and benzylidenemalononitrile were prepared in emulsion with the use of the redox system potassium persulfate–sodium bisulfite. The kinetics of copolymerization as a function of the composition of monomers, of the concentration of emulsifier and initiators, and of temperature was studied. Copolymers of high molecular weight were obtained in good yields.     

Synthesis and biological activities of some new thiazolidine derivatives containing pyrazole ring system

As a part of systematic investigation of synthesis and biologically active compounds of thiazolidine (TZD) derivatives containing pyrazole ring system, several new pyrazole–TZD derivatives 8a , 8b , 8c , 8d and 9a , 9b , 9c , 9d have been synthesized. Compounds 8a , 8b , 8c , 8d were prepared from N‐substituted TZDs 6a , 6b , 6c , 6d and 1H‐pyrazole‐4‐carboxaldehyde 7 by Knoevenagel‐type reaction. Treatment of 8a , 8b , 8c , 8d with sodium hydride at room temperature caused dimerization reaction to afford the corresponding spirocompounds 9a , 9b , 9c , 9d . All the synthesized compounds were characterized by spectroscopic analysis. In vitro, the synthesized compounds 8a , 8b , 8c , 8d and 9a , 9b , 9c , 9d were tested for their growth inhibitory activity in A549 lung cancer, B16F10 murine melanoma, and HeLa human uterine carcinoma cells and for their differentiation of 3T3‐L1 preadipocytes to adipocytes. The results showed that compound 8c possessed growth inhibitory effect of B16F10 cells (IC₅₀ = 27 μM) and compounds 9c , 9d had induction effect on the differentiation of 3T3‐L1 preadipocytes. J. Heterocyclic Chem., (2011).     

Synthesis of side chain liquid-crystalline polysiloxane containing trans-cyclohexane-based mesogenic side groups

The synthesis and characterization of nine new side chain liquid-crystalline polysiloxanes containing one cyclohexyl ring and another 2-4 aromatic rings in their mesogenic side groups are described. All synthesized polymers displayed nematic mesomorphism. Most of the polymers showed a very wide mesomorphic temperature range. The mesogenic core length has profound influence on the phase transitions of the polymers. The mesomorphic temperature range increased with increasing mesogenic core length.     

Synthesis of side chain liquid-crystalline polysiloxane containing trans-cyclohexane-based mesogenic side groups

Abstract

The synthesis and characterization of nine new side chain liquid-crystalline polysiloxanes containing one cyclohexyl ring and another 2-4 aromatic rings in their mesogenic side groups are described. All synthesized polymers displayed nematic mesomorphism. Most of the polymers showed a very wide mesomorphic temperature range. The mesogenic core length has profound influence on the phase transitions of the polymers. The mesomorphic temperature range increased with increasing mesogenic core length.     

Synthesis of alkenoic acid derivatives containing cyclopropane ring,new juvenile hormone analogs

A synthetic method is described for the preparation of new type juvenoids [$\text{2}$].     

Synthesis of new pyrazole and triazole derivatives containing a saturated γ-lactone ring

Russian Journal of Organic Chemistry -     

Thermal and spectroscopic characterization of several derivatives containing a new organic ring system

Several derivatives containing a new organic ring system, the tropane-6-spiro-5-hydantoin structure (namely 8-alkyl-8-azabicyclo [3.2.1.] octane-6-spiro-5-imidazoline-2,4-diones) have been characterized by thermal (DSC and simultaneous DTA-TG-DTG) and spectroscopic techniques (IR,¹ H-NMR,¹³ C-NMR). X-ray powder diffraction and elemental analysis were applied for structural and molecular characterization. All the compounds melt in the range 160–250°C and undergo decomposition with progressive mass loss after the solid-liquid thermal transition with molecular degradation. It was found that tropane-6-spiro-5-hydantoin derivatives with the hydantoin ring in position are thermally less stable than those containing this ring in position.One of the authors (Dr. M.V.) thanks partial financial support from CICYT through research project PA 86-0317. Thanks are extended to Ms. A. García and Mr. J. C. Rivero for artwork.