Dioxins, furans and dioxin-like polychlorinated biphenyls (PCBs) were analysed in muscle tissue from yellow phased European eel (Anguilla anguilla) from 38 sites in Belgium. Dioxin concentrations in eel vary considerably between sampling locations, indicating that yellow eel is a good indicator of local pollution levels. Measured levels of dioxin-like PCBs are much higher than those of the diox...

2,5-Dimethylfuran, 2-methylfuran, and C(9)-C(20)n-alkanes have been isolated from the kerogen of a Rupemba stromatolite. These furans could be the oldest known stable remnants of biological carbohydrates if it is possible to prove that their progenitors are as old as the rock. Experiments showed that it is improbable that these compounds are analytical artifacts or laboratory contaminations. Po...

Introduction EPA Methods 1613 (Tetrathrough Octa-Chlorinated Dioxins and Furans by Isotope Dilution HRGC/HRMS) and 8290a [Polychlorinated Dibenzodioxins(PCDDs) and Polychlorinated Dibenzofurans (PCDFs) By High Resolution Gas Chromatography/High Resolution Mass Spectrometry (HRGC/HRMS)] specify the use of a 60m 5% diphenyl 95% dimethyl polysiloxane GC column (e.g. DB-5, Rxi-5ms) for 2378 TCDD is...

The development of operationally straightforward and cost-effective routes for the assembly of heterocycles from simple inputs is important for many scientific endeavors, including pharmaceutical, agrochemical, and materials research. In this article we describe the development of a new air-stable cationic Co(III) catalyst for convergent, one-step benchtop syntheses of N-aryl-2H-indazoles and f...

* The Gas-Phase Conversion of Bio-Derived 5-Methylfurfural to 2,5-Dimethylfuran Aaron Oberg and Dennis Miller *Concern over global warming and limited oil reserves has resulted in an increased interest in the production of fuels and chemicals from biomass. Currently there is considerable interest in a class of bio-derived molecules referred to as furans. Furans contain an aromatic heterocyclic ...

R ing-closing olefin metathesis (RCM) is an effective method for the formation of cyclic alkenes (1). Recently, the aromatization of RCM products has emerged as a topic of intensive investigation (2). In this context, a variety of regiocontrolled protocols have been developed for the synthesis of diverse heteroaromatic compounds, such as pyridines, pyridazines, pyrroles, quinolines, and furans ...

A convenient Cu(I)-catalyzed cycloaddition of electron rich internal aryl alkynes and diazoacetates was discovered for the chemoselective and regioselective synthesis of tetra-substituted furans and cyclopropenes in moderate isolated yields (18-67%), and alkyne conversion (29-73%).

The addition of heteroaryllithium to various ketones followed by dehydration gave 1-(2-heteroaryl)cycloalkenes and (2-hetero- aryl)alkenes. When alkenes were treated with 10 mol% NIS, calix[4]thiophenes and calix[4]furans were obtained in good yields.

The Cu(I) halide (X = I, Br, Cl) mediated reactions of Cbz-protected cis-2-phenylethenyl-3-hydroxypyrrolidine gave novel 3-halo-2,5-trisubstituted furans in good yields, via a cyclization-halogenation, ring-opening reaction sequence. In contrast, the reactions with CuCN gave mainly the corresponding 3-cyanofuro[3,2-b]pyrrole formed from a cyclization-cyanation reaction.