Regioselective Synthesis of Natural and Unnatural (Z)-3-(1-Alkylidene)phthalides and 3-Substituted Isocoumarins Starting from Methyl 2-Hydroxybenzoates
benzene ring, have been selectively and efficiently synthesized by a new protocol which involves: (i) the conversion of methyl 2-hydroxybenzoates into the corresponding nonaflates; (ii) Pd-catalyzed alkynylation reactions of these derivatives; (iii) the conversion of the so obtained methyl 2-(1-alkynyl)benzoates into the corresponding carboxylic acids followed by a transition metal-catalyzed heteroannulation