Tetra-porphyrin molecular tweezers: two binding sites linked via a polycyclic scaffold and rotating phenyl diimide core.

The synthesis of a tetra-porphyrin molecular tweezer with two binding sites is described. The bis-porphyrin binding sites are aligned by a polycyclic scaffold and linked via a freely rotating phenyl diimide core. Synthesis was achieved using a divergent approach employing a novel coupling method for linking two polycyclic units to construct the core, with a copper(ii)-mediated phenyl boronic acid coupling found to extend to our polycyclic imide derivative. We expect this chemistry to be a powerful tool in accessing functional polycyclic supramolecular architectures in applications where north/south reactivity and/or directional interactions between modules are important. Porphyrin receptor functionalisation was undertaken last, by a four-fold ACE coupling reaction on the tetra-epoxide derivative of the core.

Microbial degradation of illicit drugs, their precursors, and manufacturing by-products: implications for clandestine drug laboratory investigation and environmental assessment.

Chemicals associated with clandestine drug laboratories are often disposed of covertly into soil, sewerage systems, or public waste management facilities. There are two significant issues relating to such dumps of materials; they might contain valuable evidence as to drug manufacture, and they might be a source of pollution. This study presents initial findings in relation to the impact microorganisms from environmental sources have upon drugs, their precursors, and manufacturing by-products. The aim of this study was to identify which chemicals associated with clandestine drug laboratories persist in the environment in order to allow forensic drug chemists to link discarded residues with the method of manufacture, and to allow the environmental impact of clandestine drug laboratories to be assessed accurately. When exposed to soil microorganisms, phenyl-2-propanone (P2P) was rapidly metabolized into mixtures of 1-phenyl-2-propanol, 1-phenyl-1,2-propanedione, 1-hydroxy-1-phenyl-2-propanone, 2-hydroxy-1-phenyl-1-propanone, and the two diastereoisomers of 1-phenyl-1,2-propanediol. On the other hand, when exposed under the same conditions, methylamphetamine sulphate (MAS) remained virtually unchanged. Implications relating to evidence gathering for forensic purposes and to environmental assessment of clandestine drug laboratories are discussed.

Stereoselective synthesis of dihydropyrone-containing marine natural products. Total synthesis and structural elucidation of (-)-membrenone-C.

[figure: see text] Three diastereomers of membrenone-C were separately prepared using a common two directional chain extending synthetic strategy. This has established the absolute and relative configuration of the natural product to be as shown in the foregoing graphic. Key steps in the synthesis of all the isomers are a stereoselective aldol coupling and reduction giving the C7-C9 stereocenters, a two direction chain extending double titanium aldol coupling, and the trifluoroacetic acid promoted double cyclization/dehydration giving the two dihydropyrone rings.

Chemical studies of rectal gland secretions of some species ofBactrocera dorsalis complex of fruit flies (diptera: Tephritidae).

Male-produced rectal gland secretions of a number of species now considered to be members of theBactrocera dorsalis complex of fruit flies have been examined by combined gas chromatography-mass spectrometry. The structures of a number of previously unreported compounds have been confirmed by synthesis and Chromatographic comparisons. Compounds identified in these secretions include fatty acids, esters, amides, keto alcohols, diols and spiroacetals. These chemical findings are in agreement with taxonomic revisions based on other criteria.