Total Synthesis of Natural Dihydropyranones: A Contribution to the Structural Elucidation of Natural Products. Coibacins A and B, Cryptomoscatones D1, D2 and E3

Cryptomoscatones D1 and D2, dihydropyranones isolated from C. mandiocanna, had their stereochemistry solved after total syntheses and comparison of spectroscopic data of natural and synthetic samples. Natural dihydropyranones coibacins A and B, metabolites isolated from marine cyanobacterium cf. Oscillatoria sp, which display antileishmanial activity and anti-inflammatory properties, were synthesized and had their absolute configuration determined. Our efforts towards the synthesis of cryptomoscatone E3, natural dihydropyranone with unknown absolute configuration, are also discussed.