Are there any cars with high compression/performance engines (i.e., that require high octane gas) that are optimized for fuel economy instead of performance?

Yes, lots.  Most of Honda's product line, same for most of the Japanese cars except for very high performance models like the Acurta NSX, Nissan Skyline GTR, most European cars, and about a third of American cars. Many of these can run on regular fuel, with a slight drop in gas mileage and maximum power compared to premium fuel. The engine computer optimizes for the fuel performance, to get the most out of what ever fuel is used. Higher compression directly affects thermodynamic efficiency, so it is generally a good thing, if the engine controls can then avoid knocking (pre-ignition of the fuel). Modern engine control computers & variable cam designs make it possible to optimize for both power and economy. The V6 engine in the new Ford Mustang allows it to get 31 mpg on the highway. It can also produce 305 horsepower, 0-60 mph times under 5.3 seconds, and a 13.7 second 1/4 mile at 102 mph. http://www.motortrend.com/roadtests/coupes/112_1003_2011_ford_mustang_v_6_test/viewall.html

High compression allows the engine to produce power more efficiently, but also requires higher quality design and construction. Most economy cars are built to a (low) budget, which may not afford the ''luxury'' of a latest technology engine - but I think the focus on emissions and fuel economy today forces pretty much all engines to optimize for fuel economy.   Take the general downsizing trend. The classic VW Audi 1.8T 20V is an example of a high compresion engine geared towards economy, as it replaced the smaller V6 engined model options. Today, we see this engine replaced by egen higher tech engines like the 1.4 TFSI, which offers the same (or higher) performance with better fuel economy and lower emissions. You can now have pretty large cars like the Skoda Superb with a 125 hp  turbocharged 1.4 litre TFSI engine. (And others with the 185 hp turbo and supercharged version)   Much of the fuel economy comes from letting small engines run under load where larger engines would run less stressed. in general terms, you could say the energy production of a piston engine is most efficient at full throttle on the torque peak - which you will see all the time in a Superb 1.4 TFSI and very rarely in an Audi RS6 (packing a large engine of a similarly advanced design)

At the expense of elaboration, these engines do exist. The easiest place to see them is in Brazil. Brazil has lots of ethanol for sale which has an octane rating of about 100 (a higher octane means an engine should be able to run a higher compression ratio). There's some engines in cars in Brazil which are optimized to run ethanol (with the octane rating of of 100). I don't know anything about their fuel consumption, but I think there's some turbo engines that get similar MPGs from ethanol that gas engines get from gas, which is an accomplishment because you can extract less energy from a gallon of ethanol than a gallon of gasoline.