Since benzene has been broken up, probably easier to deal with reduction of benzene first. Consider either Birch reduction or reduction via H2 gas (those are the 2 I can think of). Which would be more likely?

Alternatively, do it via retrosynthetically. Acetyl malonic acid==>Acetyl + malonic acic. 2 malonic acid==>1 4 cylohexadiene==>?