Determination of thorium in human urine by neutron activation

A routine procedure for the determination of thorium in urine of workers has been developed by the neutron activation method. The technique suggested by Dang, et. al. has been modified in order to reduce the costs involved and the sample processing time. The samples were irradiated in the MIT (Massachusetts Institute of Technology-Boston) reactor, in a thermal neutron flux of 8×10¹²n.cm^–2.s^–1 for 31/2 hours. Thorium-232 was determined by counting²³³Pa.     

Bridged Ferrocenes : XIII. Friedel—crafts reactions of ferrocene and alkylferrocenes with α,β-unsaturated acid chlorides

The reactions of ferrocene, butylferrocenes, and [3] ferrocenophane with α,β-unsaturated acid chlorides give mixtures of ketonic products reuslting from introduction of either a propanoyl or a propenoyl substituent or a homo- or a hetero-annular three-carbon bridge.     

Use of a highly effective intramolecular Pauson-Khand cyclisation for the formal total synthesis of (±)-α- and β-cedrene by preparation of cedrone

The cedrene carbon skeleton was directly and efficiently assembled from a simple monocyclic precursor by the strategic use of a high yielding intramolecular Pauson-Khand cyclisation reaction. A small number of further synthetic manipulations provided a concise formal total synthesis of α- and β-cedrene. The cyclisation precursor was readily prepared, with a stereoselective ketone alkenylation selectively providing the olefin required for efficient access to the natural target.