[Rutherford]

How do anhydrides activate AlCl₃? I see this first time and I need to finish this scheme.

[discodermolide]

This is just a normal Friedel-Crafts acylation.
Look on this page for the Haworth reaction
http://en.wikipedia.org/wiki/Friedel–Crafts_reaction

[Rutherford]

From looking at the scheme I tried to work out the mechanism, is it okay?
In the mechanism I wrote that the second C atom got the acyl group attached to it, but it could be any of the C atoms. How should I know which one it is?

[discodermolide]

I don't really like the acylcarbocation, but I suppose it may be stabilised by the Al.
Alkyl groups on the benzene ring are ortho/para directors, so I guess you will get some para substitution product.
Don't forget that when the pi electrons of the aromatic ring attack the acylcation you generate a cation in the benzene ring which is resonance stabilised.

[Rutherford]

"Don't forget that when the pi electrons of the aromatic ring attack the acylcation you generate a cation in the benzene ring which is resonance stabilised."

Knew that but didn't know how to draw it. Thanks very much for the help. I got one last question. In the Haworth reaction on the wikkipedia link you posted, the product is reduced and then H⁺ is added so the R-COOH group cyclizated to form a cyclic ketone. How is this possible?

[discodermolide]

Similar mechanism protonate on of the acid and cyclisation via the pi electrons as usual.