On the regioselectivity of elimination reactions in terpene derivatives

Tetrahedron ◽  
1988 ◽  
Vol 44 (10) ◽  
pp. 2913-2924 ◽  
Author(s):  
B. Badet ◽  
M. Julia ◽  
J.M. Mallet ◽  
C. Schmitz
1986 ◽  
Vol 51 (2) ◽  
pp. 436-446 ◽  
Author(s):  
Ladislav Kohout ◽  
Vijay Kumar Sethi ◽  
Jaroslav Zajíček ◽  
Alexander Kasal

Acetolysis of 3-methanesulfonyloxy-7-benzoyloxy-5β,6β-cyclopropanocholestanes with various configurations in positions 3 and 7 is described and the products are assigned structure using spectral methods. The 7-substituted compounds show greater propensity to elimination reactions than the 7-unsubstituted ones.


1982 ◽  
Vol 47 (8) ◽  
pp. 2180-2189 ◽  
Author(s):  
Jiří Sedláček

CNDO/2 calculations have been made for simple models of the adsorption of (CH3)2CHZ molecules (Z = Cl, OH, NH2, and SH) on the surface of polar catalysts. The results of these calculations and their interpretation by the method of configuration analysis in terms of uniformly localized molecular orbitals made it possible to explain satisfactorily a series of experimental facts. The mechanism and stereoselectivity of the reaction as well as reactivity trends for the series of the molecules studied are discussed.


2008 ◽  
Vol 19 (21) ◽  
pp. 2462-2469 ◽  
Author(s):  
Jiří Kulhánek ◽  
Filip Bureš ◽  
Petr Šimon ◽  
W. Bernd Schweizer

Marine Drugs ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 35
Author(s):  
Mohamed Shaaban ◽  
Ghada S. E. Abou-El-Wafa ◽  
Christopher Golz ◽  
Hartmut Laatsch

Analysis of the air-dried marine red alga Laurencia papillosa, collected near Ras-Bakr at the Suez gulf (Red Sea) in Egypt delivered five new halogenated terpene derivatives: aplysiolic acid (1), 7-acetyl-aplysiol (2), aplysiol-7-one (3), 11,14-dihydroaplysia-5,11,14,15-tetrol (5a), and a new maneonene derivative 6, named 5-epi-maneolactone. The chemical structures of these metabolites were characterized employing spectroscopic methods, and the relative and absolute configurations were determined by comparison of experimental and ab initio-calculated NMR, NOE, ECD, and ORD data, and by X-ray diffraction of 2 and 6. The antimicrobial activities of the crude extract and compounds 1–3, 5a and 6 were studied.


2021 ◽  
Author(s):  
Yichen Yu ◽  
Chenxu Wang ◽  
Liqi Wang ◽  
Cai-Li Sun ◽  
Roman Boulatov ◽  
...  

The influence of mechanical force on the rates of model reductive elimination reactions depends on the structure of the force-transducing ligand and provides a measure of geometry changes upon reaching the transition state.


Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2931
Author(s):  
Przemysław Siejak ◽  
Wojciech Smułek ◽  
Farahnaz Fathordobady ◽  
Anna Grygier ◽  
Hanna Maria Baranowska ◽  
...  

To meet the growing interest in natural antibacterial agents, we evaluated the physicochemical and biological properties of the folk medicine known as “five thieves’ oil” (Polish name: olejek pięciu złodziei). Five thieves’ oil consists of a mixture of five oils: rosemary, lemon, clove, eucalyptus, and cinnamon. In this study, we performed gas chromatography, FTIR, and UV–vis spectroscopic analysis, as well as L-a-b color tests, contact angle determination, and surface tension determination. To verify its antibacterial activity, the metabolic activity and changes in cell membrane permeability of bacteria of the genus Pseudomonas were studied. As a result, it was found that among the constituent oils, the oils of clove and cinnamon were the least volatile and, at the same time, had the strongest antibacterial activity. However, a mix of all the oils also showed comparable activity, which was even more pronounced for the oils after 4 weeks of aging. This effect can be linked to the high content of terpene derivatives such as eugenol and cinnamaldehyde, which can cause changes in bacterial membrane permeability, affecting cell activity and survival. This study is the first to characterize the constituents of the popular folk medicine five thieves’ oil, confirming and explaining its strong antibacterial activity, thus constituting a significant contribution to contemporary health education.


Sign in / Sign up

Export Citation Format

Share Document