Fluorescein: spot the fabricated intermediate

Single question

Two-step route to fluorescein: condense phthalic anhydride with two equivalents of resorcinol, then close the xanthene O bridge. Look carefully at the intermediate drawn after the first condensation.

Friedel-Crafts mechanism on resorcinol (C-acylation, not O-acylation)

Xanthene formation by intramolecular SEAr

Telling productive intermediates from wrong-connectivity ones

Find the flaw

Click the step that contains the flaw, or pick “No flaw” if you think every step is correct.

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