Reduction of the δ,ε-unsaturated aldehydes produced by tandem [2,3]-Wittig-anionic oxy-Cope rearrangement followed by stereoselective electrophilic cyclisation and reductive removal of the electrophile leads to single diastereoisomers of tetrahydropyrans. © 1997 Elsevier Science Ltd.
Diamond microcrystallites and polycrystalline films were grown on various substrates in the ambient atmosphere with an oxygen-acetylene welding torch. Growth is examined as Nike Air Max 90 Em
a function of substrate position and temperature, and gas flow ratio. The deposited Air Max 1 Fb
material was analyzed with Raman spectroscopy, X-ray diffraction and electron microscopy.
Multivariate cointegration is used to generate the long-run forecast of the dollar/DM exchange rate. It is shown that while the random walk model outperforms the monetary structural models in the short run, the latter, based on the error-correction model, outperform the former in the long run.
γ-irradiation at 10,000 rads or even less will prevent the sprouting of potatoes, and its use on the commercial scale appears to be technically feasible. Its widespread employment on individual farms would perhaps be difficult and it has other disadvantages. For instance it may increase fungal rotting, and it accelerates the sweetening and tissue breakdown which normally occur after prolonged storage.