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36. Synthetic transformations of isoquinoline alkaloids. 1-alkynyl-3,6-dimethoxy-N-methyl-4,5α-epoxy-6,18-endoethenobenzo[i]isomorphinans and their transformations.

Author

Bauman, V. T., Shul’ts, E. E., Kononchuk, V. V., Bagryanskaya, I. Yu., Shakirov, M. M., and Tolstikov, G. A.

Subjects
*PHASE transitions, *ISOQUINOLINE synthesis, *ALKALOID synthesis, *EPOXY compounds, *CHEMICAL reactions, *REGIOSELECTIVITY (Chemistry), *N-Iodosuccinimide
Abstract

The reaction of thebaine with 2-bromo-6-methyl-1,4-benzoquinone regioselectively afforded 6,18- endo-etheno-9-methyldihydrothebainehydroquinone. Iodination of 6,18- endo-ethenodihydrothebainehydroquinones with N-iodosuccinimide in trifluoroacetic acid was also selective, and the corresponding 1-iodo derivatives were formed. The main reaction pathway in the halogenation of 6,18- endo-ethenodihydrothebainehydroquinone with iodine chloride was chlorination of the fused hydroquinone fragment. The Sonogashira reaction of 1-iodo-6,18- endo-ethenodihydrothebainehydroquinones with trimethylsilylacetylene and subsequent desilylation gave 1-ethynyl-6,18- endo-ethenodihydrothebainehydroquinones. 1-[3-(4-R-Piperazin-1-yl)-propynyl]- and 1-{3-[2-(pyridin-3-yl)piperidin-1-yl]propynyl}-6,18- endo-ethenodihydrothebainehydroquinones were synthesized by the Mannich reaction of acetylenic derivatives of dihydrothebainehydroquinone with piperazine and anabasine in the presence of formaldehyde, catalyzed by copper(I) compounds. The reaction of 1-iodo-6,18- endo-ethenodihydrothebainehydroquinone with N-methylpiperazine and formaldehyde was accompanied by copper-catalyzed oxidative homocoupling. [ABSTRACT FROM AUTHOR]

Published
2013
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47. Replication of RNA bacteriophages in the presence of rifamycin

Author

Bauman, V, Pumpen, P, Dishler, A, and Gren, E J

Abstract

Replication of RNA bacteriophages in the presence of rifamycin was studied in different Escherichia coli strains that vary in RNase content but are not isogenic: AB259 RNase+, Q13 RNase I- PNPase-, AB105 RNase I- RNase III-. It was found that rifamycin did not affect characteristics of phage replication such as the general pattern of viral RNA synthesis and intracellular development of the phage. These characteristics are strain specific and independent of the cell growth rate, which defines only phage release. The inhibition of cell division by rifamycin interfered with the release of the phage and thus produced an apparent effect of rifamycin on phage replication.

Published
1978
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