Electrophilic aromatic substitution of furan favors addition to the 2-position because the intermediate cation is more stable than addition to the 3-position. Draw the mechanism arrows for the Friedel-Crafts acylation of furan. In steps 1-3 draw the curved arrows to show the formation of the acyliumion electrophile and acylation of furan. In steps 4 and 5 draw all resonance structures for the intermediate cation, then showing reaction of the last resonance structure with FeCl4 to generate the final product. Make sure to draw lone pairs of electrons for all species and nonzero formal charges.