Method for the rapid synthesis of highly functionalized 2-hydroxy-1-naphthoates. Syntheses of the naphthoic acid components of neocarzinostatin chromophore and N1999A2.

We describe a four-step sequence for the synthesis of complex 2-hydroxy-1-naphthoic acids involving Z-selective olefination of benzaldehyde derivatives with a novel dioxolenone-containing phenyl phosphonate reagent, followed by dioxolenone cleavage with alkaline trifluoroethanol and oxidative cyclization (Mn(OAc)(3)) of the resultant trifluoroethyl beta-keto esters. [reaction: see text]