Novel synthetic methods are vital to the work of a host of key chemical disciplines; from new materials and nanotechnology to pharmaceuticals, practitioners constantly need cleaner, greener, milder and more efficient ways to synthesize their chosen targets. In this proposal, we seek to develop, and then apply to some very challenging scenarios, a set of particularly powerful and beyond the state-of-the-art new methods, using singlet oxygen, that will meet all these tough criteria.Singlet oxygen is a remarkable reagent; it is a natural, cheap, green and atom-efficient oxidant. It also makes an ideal initiator for cascade reaction sequences through which molecular complexity is enhanced very rapidly and effectively. With this chemistry protecting groups and toxic heavy metal oxidants, both normally associated with the construction of molecules rich in oxygen functionality, are not needed.In the projects described within this proposal, singlet oxygen will be manipulated to orchestrate a diverse range of cascade reaction sequences, and “super cascade” reaction sequences, by which complex polyoxygenated and polycyclic molecular architectures will be synthesized, from very simple and readily accessible furan precursors, in one-pot. Polyoxygenated-polycyclic motifs are common synthetic targets across a range of disciplines. In our case, we will focus research efforts towards bioactive natural products because these highly complex and intricate structures provide the best, and most challenging, testing grounds for any new set of chemical methods. The natural products chosen belong to the azaspiracid, pinnatoxin/pteriatoxin, spirolide and pectentoxin families, respectively.We also hope to further promote the widespread application of these singlet oxygen-based chemical solutions to a host of problems by developing a prototype Continuous Flow Reactor that will facilitate large scale photooxygenations.