The cyclization reaction that we envisioned to form the C3-C4 bond and install oxidation at C28 was a borylative Heck. Such reactions have recently been developed, including by the Lautens group (Figure , right), showcasing feasibility to form all-carbon quaternary stereocenters while installing a boronic ester at the adjacent carbon center (14→15). This boronate could serve as a precursor for an alcohol via a simple and chemoselective oxidation. Mechanistically, this reaction would begin with oxidative addition to vinyl iodide I (Figure , left) to provide vinyl palladium intermediate II.