Synthesis of Diversonol

Significance

Diversonol, a secondary metabolite isolated from Penicillium diversum, possesses a carbon scaffold also found in the secalonic acids, isolated from Claviceps purpurea. These myco­toxins exhibit a variety of biological activities and the development of efficient routes to their synthesis is desirable. Noteworthy in this synthesis is the oxa-Michael-aldol condensation (B. Lesch, S. Bräse Angew. Chem. Int. Ed. 2004, 43, 115-118) used to prepare tetraoxanthenone B.