Cyclization of undec-10-enoic acid by polyphosphoric acid

Undec-10-enoic in the presence of polyphosphoric acid is shown to yield a mixture of 2-n-hexylcyclopent-2-enone and 2-n-pentylcyclohex-2-enone.     

The synthesis of 3,4-disubstituted furan prostanoids

The reaction of 4-phenyloxazole with methyl 10-oxodec-8-ynoate is reported as the key step in the synthesis of 3,4-disubstituted furan prostanoids.     

Analysing maintenance data to gain insight into systems performance

The high cost of maintenance in the processing industry implies the need for optimal planning of maintenance strategy. In order to achieve this there is a need to understand the underlying failure processes, which are often very complex. In this paper, a new semi-parametric approach, combining Cox regression with density kernal smoothing, is introduced to estimate the underlying performance. The approach has been applied to several processes and it allowed insight into each process, which would not have been achieved if traditional approaches had been used. Particularly, the refurbishment of processes had a significant impact on the rate failure. This paper concludes by assessing this impact of refurbishment on the maintenance programme.     

Modelling the purchase propensity: analysis of a revolving store card

We investigate the incremental roles of information that becomes available only after a revolving loan has been granted in explaining and predicting the time taken until the borrower makes a second purchase. Using data relating to a store card, granted around the time of first purchase and used in Belgium, we find that characteristics of a first purchase and remaining credit available for use enhance the explanatory and predictive power of application characteristics. The relationship differs between good and poor payers.     

The preparation and electrochemistry of manganese(II) complexes of an unsaturated pentadentate macrocyclic ligand

The preparation of a series of six and seven coordinate manganese(II) complexes [Mn^(II)(L)X]⁺, and [Mn^(II)(L)X₂]^2? (X = halide, water, triphenylphosphine oxide, imidazole, 1-methyl imidazole and pyridine) incorporating the pentadentate planar macrocylic ligand L is described. Cyclic voltammetry of these complexes in acetonitrile each shows a reversible one-electron reduction wave near - 1.4 V vs a Ag/AgNO₃ reference electrode. Quantitative reduction of these complexes by controlled potential electrolysis at a platinum gauze at - 1.4 V yields the corresponding one-electron reduction products which have been shown by ESR spectroscopy to be manganese(II)-ligand radical species, the electron being thought to reside on the di-imino pyridine moiety of the macrocyclic ligand. No metal reduced species could be isolated even in the presence of π-acceptor ligands such as CO or phosphines.