Switchable Synthesis of α- or β-Keto Naphthalenes via Gold-Catalyzed Divergent Cycloisomerization of 1,6-Diyn-3-ols and Its Application in the Total Synthesis of Justicidin B and Taiwanin C.
A switchable divergent gold catalysis is described that employs 1,6-diyn-3-ols as a common starting material for the regioselective synthesis of β-keto and α-keto naphthalenes. Under Au(I) catalysis, the α-keto naphthalenes are obtained regioselectively. In contrast, the β-keto naphthalenes are obtained as the major pr...