Activation analysis of high-purity silicon

³²P was separated from the irradiated silicon matrix as ammonium phosphomolybdate and the activity was measured with a GM tube or on a plastic scintillator. The second-order interference was taken into consideration. Research associate of the N.F.W.O.     

Indolo[3,3a,4-gh]chinoline und 10a, 6a-Iminopropano-indolo-[3,3a,4-gh]chinoline. Stereospezifische Synthesen und Umlagerungen. Teil II. 9. Mitteilung über synthetische Indolverbindungen

Alkaline hydrolysis of 1-benzyl-4, 4-dicyanoethyl-5-oxo-1,3,4,5-tetrahydro-benzo-[cd]indole under controlled conditions leads to 4-benzyl-4,6,7,8-tetrahydro-10a, 6a-iminopropanoindolo[3,3a,4-gh]quinoline-9(10H),12-dione ( 2a ), the first representative of such a ring system. Alkylation of this di-lactam affords the N-monoalkyl ( 2b ), the N, N'-dialkyl ( 3 ), and the N, O-dialkyl ( 4 ) derivatives according to the conditions employed. Treatment of compounds such as 2 with sodium in liquid ammonia results in the opening of one of the lactam rings by a stereoelectronically controlled reductive cleavage of the benzylamine bond; subsequent protonation proceeds stereospecifically to give trans-octahydroindolo[3,3a, 4-gh]quinolines (viz. 5 ). The NMR. spectra and the mechanism of the reductive ring opening are discussed.     

A study of the anthocyanins of hibiscus hybrids

Chemistry of Natural Compounds -     

Role of tetraethoxysilane hydrolysis and polycondensation catalysts in synthesis of wide-pore silica gels

A study has been made of the effect of combining tetraethoxysilane hydrolysis and polycondensation catalysts operating by different mechanisms on the texture parameters of synthesized silica gels. The effect of hydrothermal treatment of a fluorine-containing silica hydrogel on the thermal stability of the xerogel texture was demonstrated.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 30, No. 2, pp. 95–98, March–April, 1994.     

Synthesis of 6-arylspiro[tetrahydropyran-3,1′-cyclobutane]-2,4-diones

Methyl 1-(2-bromo-2-methyl-1-oxopropyl)-, 1-(1-bromocyclopentylcarbonyl)-, and 1-(1-bromocyclohexylcarbonyl) cyclobutanecarboxylates reacted with zinc and aromatic aldehydes to give, respectively, 7-aryl-2,2-dimethyl-6-oxaspiro[3.5]nonane-5,9-diones, 11-aryl-12-oxadispiro[3.1.4.3]tridecane-5,13-diones, and 12-aryl-13-oxadispiro[3.1.5.3]tetradecane-5,14-diones.     

X-ray crystallographic investigation of the adduct of 1-demethylamino-2-(4-bromophenyl-2H-isoindole with N-phenylmalemide

An unusual path for the reaction of 2-aryl-1-dimethylamino-2H-isoindoles with N-R-maleimides, leading to the imides of l,2-dihydronaphthalene-2,3-dicarboxylic adds, was established by x-ray crystallographic analysis.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 614–618, May, 1992