Asymmetric Total Synthesis of (−)‐Erogorgiaene and Its C‐11 Epimer and Investigation of Their Antimycobacterial Activity

A short, nine‐step, highly enantioselective synthesis of (?)‐erogorgiaene and its C‐11 epimer is reported. The key stereochemistry controlling steps involve catalytic asymmetric crotylation, anionic oxy‐Cope rearrangement and cationic cyclisation. (?)‐Erogorgiaene exhibited promising antitubercular activity against multidrug‐resistant strains of Mycobacterium tuberculosis.     

Beyond the Dimer and Trimer: Tetraspiro[2.1.25.1.29.1.213.13] hexadecane‐1,3,5,7‐tetraone—the Cyclic Tetramer of Carbonylcyclopropane

Tetraspiro[2.1.2⁵.1.2⁹.1.2¹³.1³]hexadecane‐1,3,5,7‐tetraone 4 , a unique tetraketone containing a cyclooctane core and four spiroannelated cyclopropane moieties, represents the previously unknown cyclotetramer of carbonylcyclopropane. For this purpose oxidation of the parent polyspirocyclic hydrocarbon was examined under various oxidative conditions, and the reactivity of oxidants towards methylene groups of the eight‐membered cycle, activated by adjacent spirocyclopropane rings, was evaluated and contrasted. Whereas the treatment of tetraspirohexadecane with ozone resulted in monooxidation, its reaction with methyl(trifluoromethyl)dioxirane afforded the product of four‐fold oxidation, triketoalcohol 10 . Subsequent oxidation of the latter with Dess–Martin periodinane gave the target tetraketone 4 .     

Chemical Industry,the Environment,and Russian Provincial Society: The Case of the Kokshan Chemical Works (1850–1925)

This article explores interactions between the chemical industry, the environment, and Russian provincial society in the late nineteenth and early twentieth centuries, using the example of the Kokshan chemical works, in the Elabuga District, Viatka Province, Russian Empire (today Mendeleevsk District, Republic of Tatarstan, Russian Federation). The plant’s location facilitated its rapid development due to a number of factors, including a cheap labour force, the availability of raw materials, and the absence of local competition. However, the factory’s development came in conjunction with the deterioration of the environment and subsequent health problems for employees and the surrounding population. Conflicts connected with the Kokshan works illustrate differences between this case and similar examples in Russia and Europe. In Viatka Province, the local community remained mostly silent regarding these issues, and made no demands for improving sanitary control and working conditions or reducing pollution; rather, it was distant activists who personally suffered no harm who intervened in the interest of social justice. The history of the company reflects the contrast between the transfer of European technological innovations to Russia and laborious efforts to increase national wealth on the one hand, and the exploitation of the environment and endangerment of workers’ health on the other.     

Unravelling RNA–Substrate Interactions in a Ribozyme‐Catalysed Reaction Using Fluorescent Turn‐On Probes

The Diels–Alder reaction is one of the most important C?C bond‐forming reactions in organic chemistry, and much effort has been devoted to controlling its enantio‐ and diastereoselectivity. The Diels–Alderase ribozyme (DAse) catalyses the reaction between anthracene dienes and maleimide dienophiles with multiple‐turnover, stereoselectivity, and up to 1100‐fold rate acceleration. Here, a new generation of anthracene‐BODIPY‐based fluorescent probes was developed to monitor catalysis by the DAse. The brightness of these probes increases up to 93‐fold upon reaction with N‐pentylmaleimide (NPM), making these useful tools for investigating the stereochemistry of the ribozyme‐catalysed reaction. With these probes, we observed that the DAse catalyses the reaction with >91 % de and >99 % ee. The stereochemistry of the major product was determined unambiguously by rotating‐frame nuclear Overhauser NMR spectroscopy (ROESY‐NMR) and is in agreement with crystallographic structure information. The pronounced fluorescence change of the probes furthermore allowed a complete kinetic analysis, which revealed an ordered bi uni type reaction mechanism, with the dienophile binding first.     

Chiral recognition in solution and the gas phase. Experimental and theoretical studies of aromatic D- and L-amino acid–Cu(II)–chiragen complexes Jennifer L. Seymour František Tureček Andrei V. Malkov Pavel Kočovský Journal of Mass Spectrometry 2004; 39: 1044–1052

The original article to which this Erratum refers was published in Journal of Mass Spectrometry 2004; 39: 1044–1052.