textStudies directed toward the total synthesis of the cytotoxic steroidal alkaloid
cortistatin A were carried out. In a model system, it was determined that a sequence of
reactions involving a lithiocyclopropene addition-intramolecular [4 + 2] cycloaddition
cascade and subsequent cyclopropylcarbinyl rearrangement allowed for ready access to
the BCD rings of the core steroid. Implementation of this methodology en route to the
fully functionalized natural product proved an effective means for the elaboration of the
A ring carbocyclic framework.Chemistry and Biochemistr