Over the years, outbreak of livestock diseases caused by mold-damaged animal feeds and foodstuffs have become a matter of concern, and led to the the subsequent discovery of the toxic principles. A possible association with disease and cancer in humans further increased the interest and awareness of mycotoxins in general. Accordingly, chemical and biological studies of these toxins have become increasingly important. Our main objective is to develop total syntheses of a structurally unique group of diverse mycotoxins. Our program seeks to develop new routes which will allow for synthesis of target compounds and various synthetic analogs in significant quantities. This proposal includes synthetic routes to swainsonine, a powerful mannosidase inhibitor, verrucosidin, a potent neurotoxin, and citreoviridin and aurovertins, potent mitochodrial ATPase inhibitors. Particular emphasis will be placed on the regulation of stereochemistry during the construction of acyclic molecular subunits. The key synthetic methodology to be developed and utilized involves an efficient stereocontrol at the prochiral sp2 sites by an allylic oxygen substituent. Nitrone cycloadditions, osmylations and chelation controlled Claisen rearrangements are included.