Synthesis of decaline analogues of isovelleral
Decaline analogues of the bioactive fungal sesquiterpene (+)-isovelleral (1a), retaining the bicyclo[4,1,0]hept-2-en-1,2-dicarbaldehyde system, were prepared, and their cytotoxic and antimicrobial activities were compared with those of the natural product. While the two isomers (+/-)-2 and (+/-)-3 were as active as isovelleral (1a), the isomer (+/-)-4 was approximately 10 times less potent.