PHOTO-CHEMICAL APPROACH TO THE SYNTHESIS OF NATURAL-PRODUCTS

The use of photochemical conversion of one molecule into an other as an approach to tine chemicals showing interest as new synthons, or as a key-step in multiple-steps synthesis of natural products is emphasized. The following topics are reviewed: photocycloaddition (photoannelation, ring-enlargement, access to grandisol, addition of allene to polycyclic enones), intramolecular cyclisation (electrocyclisation of benzylidene urethanes, photolytic cyclodehydrohalogenation, heteroatom directed photoarylation), molecular rearrangement of cross-conjugated cyclohexadienones, ring-opening of cyclanones and conjugated cyclohexadienones into terpenoids, formation and thermal decomposition of oxetanes, functional transformations. © IUPAC