Abstract: The syntheses of isocoumarins 9a and 9b, known penultimate precursors for the toxic fungal metabolites ochratoxin B (3a) and ochratoxin A (3b), respectively, are reported. The syntheses are initiated from 0-aryl carbamates 4a, b and proceed through intermediates 5c, d, 7c, d, and 8b, c by a synthetic design that involves comprehensive application of the directed ortho metalation reaction on 0-aryl carbamates and tertiary benzamides.
