ketone products can be efficiently constructed by sequential Friedal-Crafts acylations with phosgene. a- draw an arrow…

ketone products can be efficiently constructed by
sequential Friedal-Crafts acylations with phosgene.
a- draw an arrow pushing mechanism for the double acylation and
predict the final product
b-draw the major resonance contributor of the sigma complex formed
in the first acylation
excess AICl3 Cl︿Cl phosgene