Synthetic studies of the Thio-Nazarov Cyclization Biomimetic Total Syntheses of Shimalactones and Exiguamines Synthesis of Photoswitchable Dopamine Analogs.

摘要

Part 1 of this thesis describes progress towards thio-Nazarov electrocyclization utilizing substrates with a removable docking group, such as alkyl sulfides, for Lewis acid coordination. This work builds on the successful asymmetric catalysis of Nazarov electrocyclization using non-removable docking groups for coordination of Lewis acids.;Parts 2 and 3 of this thesis describe the biomimetic syntheses of the natural products shimalactones and exiguamines respectively. While the synthesis of alkaloids exiguamines A and B is an improvement of our previous work, the synthesis of polyketides shimalactones A and B is their first synthesis and describes a novel intramolecular addition of a beta-ketolactone across a diene. Both syntheses feature pericyclic reactions in their key step biomimetic cascade reactions.;Part 4 of this thesis describes the synthesis of photoswitchable derivatives of dopamine, containing azobenzenes.