A convergent total synthesis of (±)-γ-rubromycin.

An expeditious convergent total synthesis affords (±)-γ-rubromycin (1) in 4.4% overall yield. The longest linear sequence is 12 steps from commercial starting materials. The effort highlights a remarkable late-stage oxidative [3 + 2] cycloaddition for construction of the spiroketal, a regioselective carbonyl methylenation, a boron tribromide promoted deprotection, ortho- to para- naphthoquinone spiroketal rearrangement, and a tautomerization sequence.