Abstract
The synthesis of the ABDE ring system of spiroaspertrione A is reported. Construction of the DE ring system features a cycloaddition-lactonization strategy, followed by an efficient cyclopropanation and subsequent ring expansion to construct the cycloheptylfuranone core. A Michael addition was employed to join the AB and DE fragments, which ultimately revealed a strategy for the introduction of a second Michael acceptor, which we envision to be a key precursor to spiroaspertrione A.