Hilbert symbol for Lubin-Tate formal groups. II

Explicit formulas are obtained for the generalized Hilbert symbol on the group of points of a formal Lubin-Tate group, simultaneously covering the cases of even and odd characteristics of the residue field.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 132, pp. 85–96, 1983.     

Nature of the transformations of oleanolic acid in an acid medium

3-Trifluoroacetoxyoleanolic acid and 3-trifluoroacetoxyolean-13(18)-en-28-oic acid have been isolated from the mixture of the products of the transformation of oleanolic acid in a trifluoroacetic acid medium, and their structures have been established with the aid of IR, PMR and mass spectra. The formation of these products indicates an unambiguous route of the stabilization of the intermediate carbocation with the charge on the C-13 atom. The hydroxy group at C-3 is esterified by the trifluoroacetic acid.All-Union Scientific-Research Institute of Medicinal Plants, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 320–323, May–June, 1986.     

A metal reactor for the diaphragm method with chambers providing complete mixing

A new metal reactor with two chambers in which complete mixing of gases is achieved has been developed for use in the diaphragm method. This apparatus is suitable for the determination of the effective diffusion coefficient and its temperature dependence. It can also be used to determine the type of transport, the gas permeability coefficient and to investigate the macrokinetics of catalytic processes.

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Migration of the exocyclic double bond in terpenoid coumarins of the iresane series

In terpenoid coumarins of the iresane series with an exocyclic double bond, migration of the double bond into the ring with the retention of the configuration of the substituent in position 1 is observed in an acid medium. The reaction has been performed in CF₃COOH and has been monitored by the PMR method. Badrakemin has yielded conferol, badrakemone has yielded conferone, badrakemin acetate has yielded conferol acetate, colladonin has yielded moschatol, and farnesiferol A and gummosin have yielded the corresponding isomers with endocyclic double bonds. The rate of the reaction is affected by the nature of the substituent at C-6. The presence of a keto group increases the time of isomerization to 1.5 h as compared with the 5–10 min for compounds with an OH group at C-6. The increase in the time of the reaction leads to the formation of byproducts. The reaction does not take place in CH₃COOH.     

Synthesis and structure of complexes of gold(III) with sulfur-containing crown ethers

The 11 complexes of chloroauric acid with three sulfur-containing crown ethers, 4,7,13,16-tetraoxo-l,10-dithiocyclooctadecane (DTTO18C6) and its oxidized derivatives, the - and -forms of 4,7,13,16-tetraoxo-l,10-disulfoxocyclooctadecane (DSF18C6), have been synthesized and investigated by physicochemical methods. It is demonstrated that in all three cases the metal ion does not enter into the cavity of the macrocycle. In the case of DTTO18C6 complex formation takes place via the sulfur donor atoms of the macrocycle, in the case of the - and -forms of DSF18C6 via the oxygen of the sulfoxide group. It is assumed that gold as the complex-forming metal plays a role in the stabilization of the cis-form of the macrocyclic sulfoxide.Translated from Teoreticheskaya i Éksperimental/naya Khimiya, Vol. 26, No. 5, pp. 637–640, September–October. 1990.     

Unprecedented base-promoted cascade transformation of a pyrimidinone derivative into a novel tricyclic bis-diazepinone

In the presence of strong bases (NaH, DBU, KOH), ethyl 4-chloromethyl-6-methyl-2-oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate, 4, is transformed into a novel tricyclic compound, diethyl 9-methyl-5-methylene-3,11-dioxo-2,3,4,5,6a,7,10,11-octahydro-1,6-methano[1,3]diazepino[1,7-e][1,3,5]triazocine-6,8(1H)-dicarboxylate, 5, as a result of a cascade reaction.     

Condensation of 1,3-thiazan-2,4-dithione

Thiopropiorhodanine condenses at the 4-thioketo group with quaternary salts of 2-methyl- and 2-methyl-5-methoxybenzothiazole to form merocyanins. N-Ethyl- and N-phenyl derivatives do not undergo this reaction.See [1] for communication I.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 228–229, February, 1971.