Friedel-Crafts alkylations free phenols, alkylation

The first step in the sequence may involve Friedel-Crafts-type condensation of resorcinol with the enolate of 10 to afford the unsaturated ester, 11. Alkylation of the free phenol on 12 by means of ethyl bromoacetate affords chromonar (13). ... 

In the Friedel-Crafts realm, Lou and coworkers reported on the activity of Mg-phosphoric acid-based binary catalyst in the alkylation of free phenols via Michael addition of p,y-unsaturated a-ketoesters 25 [41], Despite the real structure of the binary organometallic catalytic species is still unknown, excellent levels of chemical and optical outcomes were achieved in the titled process (Scheme 5.24). To be mentioned that neither the BA nor MgF alone could promote the model reaction at any extents, proving the formation of a concertedly activated catalytic aggregate between the two acids. 

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