Total synthesis of isodeoxypodophyllotoxin using the Me3Sn radical initiated carbocyclization

The lactone portion of the podophylotoxin framework was assembled from a free-radical carbocyclization reaction, and the target structure was constructed based on intramolecular Friedel–Crafts reaction. In addition to isodeoxypodophyllotoxin, there were formed unusual tri- and tetracyclic compounds. Key words: free-radical carbocyclization, C—Sn bond cleavage, podophyllotoxin analog.