Research objectives and content
Since early work established between vitamin D3 and rickets, the importance has emerged of vitamin D3 and the hormonally active form, la,25-dihidroxyvitamin D3 1 in a number of disease funtions. recent research suggests that 1 has potential as a treatment for psoriasis, and for certain cancers. effective chemotherapy must combine lo hypercalcemic action with high anti-cancer activity and the search has begun for analogues which meet these criteria.
We propose to develop a general synthetic strategy for the assembly of analogues of 1. The strategy has been devised so as to combine optimal convergence, brevity and stereoselectivity in such a way that it will be possible to synthetize a structurally diverse range of vitamine D3 analogues hitherti inaccesible using established semi-synthetic or degradation based methods. The key disconnections are shown in Scheme. It is proposed to established the intermediancy of 'southern hemisphere' and 'northern hemisphere' fragment 3 and 4, which will be joined using transition metalmediated coupling reactions to give structures exmplified by triene 2. The functionality necesary for the connecting of 3 and 4 in this way will be incorporate directly from the strategy-level transformations used in their synthesis, requiring only minimal manipulation of the products of these reactions immediately prior to the crucial coupling reaction. attachment to C-22 of a variety of nuclephilic side-chain units will be accomplished using established methods of olefination and alkylation.
Training content (objective, benefit and expected impact)
This project will be very useful to the training of the candidate because I should develop synthetic methods which are important for our research group in Spain. Secondly, I will be working in Medicinal Chemistry that is the main object I would like work in my future research programme. Finally, I will have the opportunity of using materials and instruments that I did not use in my Ph.D. studies. We believe that once we have established the scope for the elaboration of (1), many related biologically important analogues will ill succumb to total synthesis via a similar strategy.
Links with industry / industrial relevance (22)
Professor Craig has received several medals and Awards from the Cheical Industry for his research accomplishmentes, and consults widely for the Chemical Industry on several aspect of organic synthesis. In the same time, and following one of the EC 's guidelines, the project would enanble the the transfer of information a positive results toward the european Pharmaceutical Industry.