Titolo della tesi: Studies for the synthesis of (+)-Oryzalexin S and (±)-C75 derivatives
(+)-Oryzalexin S is a stemarane diterpenoid isolated from Oryza sativa which produces it if attacked by the fungus Pyricularia oryzae, or exposed to heavy metals or irradiated by ultraviolet light. Its structure was elucidated by means of 2-D NMR experiments but the absolute configuration assignment is still unknown. (+)-Oryzalexin S is the first stemarane type phytoalexin to be reported and it has not yet been synthesized, thus constituting an interesting and challenging.
The diastereoselective synthesis of an advanced intermediate of (+)-Oryzalexin S from (S)-4a-methyl-3-methylene-5-oxo-2,3,4,4a,5,6,7,8-octahydronaphthalene-1-carbaldehyde has been carried out. The latter was obtained enantioselectively by an intramolecular aldol reaction testing different amino acids and conditions on 4-((1-methyl-2,6-dioxocyclohexyl)methyl)pent-4-enal prepared by two different routes from 2-Iodoethanol. After optimizing the reaction conditions, a mechanism study was conducted on the cyclization and dehydration steps.
In 2019 I moved to the University of Barcelona where I worked for six months on the synthesis of some derivatives of (±)-C75, a powerful anti-tumor and anti-obesity drug.
I have prepared three derivatives in their racemic form, one of them has been tested on the cancer cell line OVCAR-3 obtaining, however, unsatisfactory results.