AbstractsChemistry

Polyhydroxylated fragments are ubiquitous in natural products possessing interesting biological properties. Two patterns can be distinguished: skipped and contiguous polyols. On the subject of contiguous polyols, it was decided, at the onset of this work, to investigate possible pathways to access, at will, all four possible diastereoisomers of a 1,2,3-triol. The likelihood of obtaining amino diols was also envisioned. Therefore we examined the addition of achiral allylstannanes (type II, III) to functionalized chiral aldehydes. This approach led to the synthesis of anti-syn (type II allylstannane) and syn-anti (type III allylstannane) triols as well as syn-syn amino diols (type II allylstannane) with good diastereoselectivities. This efficient new tool was then employed in the total synthesis of natural bioactive products. The first target was (-)-cleistenolide and its synthesis was accomplished in 12 linear steps starting from D-mannitol. The formal total synthesis of a second natural compound, herbarumin I, was achieved and required 9 linear steps starting from 1-pentene. This tool was also used in the synthesis of 2,6-trans-THPs, a part of our synthetic endeavour towards the total synthesis of amphidinol 3. Our efforts in their preparation and subsequent functionalization complete this thesis. (SC - Sciences)  – UCL, 2014