New synthetic approaches towards the synthesis of morphine

In the introduction, previous synthetic approaches to morphine are reviewed; a brief outline of the physiological properties of morphine and its analogues is also presented. Chapter two describes the model studies conducted in our laboratories and then gives an account of the efforts to obtain a total synthesis. The key step, a 1,3-sigmatropic rearrangement, failed and the reasons for that are discussed briefly. Chapter three gives an account of the efforts to secure the furan ring system of morphine by the opening of an epoxide. This was not achieved, however, some interesting reactions emerged from these studies. These included an intramolecular Alder-ene reaction, magnesium bromide initiated electrophilic cyclisation onto a aromatic ring, palladium catalysed alkyl substitution onto a aromatic ring as well as others. Chapter four describes the efforts to secure the furan ring of morphine by an intramolecular radical cyclisation reaction. These were not clean reactions and were plagued by five and six membered ring formation as well as tandem cyclisations. Chapter five concerns the possibility of utilising an intramolecular Heck reaction as a key step towards a total synthesis of morphine. Model studies were conducted which indicate that the proposed route is feasible.(DX89587)