Dearomatising Additions: Mechanism, Scope and Applications

Flat aromatic compounds are often cheap and readily available, making them useful starting materials, especially if they can be converted in a simple manner to non-aromatic products. There are relatively few reactions which do this, especially in a manner which also controls shape (stereoselectivity). We have recently discovered a way of carrying out addition reactions to simple aryloxazolines with loss of aromaticity, and in this proposal we seek to develop the dearomatising addition to aryloxazolines as a generlly useful and versatile synthetic method. To do this, we shall investigate the mechanism of the addition. The reaction almost certainly proceeds via radical intermediates containing single unpaired electrons, and the intermediates in the reaction pathway can therefore be studied by Electron Paramagnetic Resonance (EPR) and Electron-Nuclear Double Resonance (ENDOR). Using these and a selection of other spectroscopic techniques we will establish (a) how the reaction works and (b) which reaction partners might best be used to extend the reaction's scope. Having doen this we will move on to apply the dearomatising addition reaction to the synthesis of valuable bioactive compounds such as carbacyclic sugar analogues (many of which are potential antiviral agents).