Chemoenzymatic Approaches to the Montanine Alkaloids: A Total Synthesis of (+)-Brunsvigine

The readily available and enzymatically derived cis-1,2-dihydrocatechols 3a and 3b have been elaborated over 17 steps, including a novel radical addition/elimination sequence, into the enantiomer, (+)-1, of the montanine alkaloid brunsvigine [(-)-1].