Gold-Catalyzed Diastereoselective Formal Intermolecular [4 + 2 + 1] Cycloaddition of 1,3-Dien-8-yne with Diazo Ester

The first example
of gold-catalyzed formal intermolecular [4 +
2 + 1] cycloaddition was developed using 1,3-dien-8-yne as C4 and
C2 units and diazo ester as the C1 unit, which provides expedient
access to a series of structurally complicated [5.3.0] bicyclic adducts
in moderate yields with moderate to high diastereoselectivities. The
key route involved a cascade process of dienyne cycloisomerization,
cyclopropyl gold carbene’s trapping, and subsequent divinyl
cyclopropane (DVCP) Cope rearrangement.