Total synthesis of serofendic acids A and B employing tin-free homoallyl-homoallyl radical rearrangement

Total syntheses of serofendic acids A (1a) and B (1b) are described. The key strategic element of the approach involves the novel tin-free homoallyl-homoallyl radical rearrangement of 5 for the construction of bicyclo2.2.2]octane ring system 4. In addition, the conversion of methyl atisirenoate 2 to serofendic acids A (1a) and B (1b) was achieved on the basis of the Michael reaction of sodium thiomethoxide.reaction: see text]