There are plenty of GoHz pure sine wave inverters that will convert DC to 60 Hz / 50 Hz AC power. for power values, you will have to amplify it with a good Push-Pull complementary couples. Any other way will not give you a PURE sinusoid, just approximations, and lots of harmonics. I did it many times successfully in graduate school and at 1000 watt pure sine wave power inverter projects. You need to use an inverter to convert DC source to an AC output. To have a pure sine wave output, would will need a 1000w sine wave inverter and output filters to reduce harmonic content to the load.

A simple Wien-bridge oscillator will do exactly that! Two capacitors, two resistors, and an op-amp is basically all you need. If you want more power, you can just attach a 1000w pure sine wave inverter to the output. The efficiency of this setup is limited, but it can give you a near perfect sine wave from your DC source.

There are plenty of DC to AC sine wave power inverter systems even for large power requirements - the more elements they have in their system the closer to a 1000w pure sine wave power inverter. The best results are obtained with an inductive load. The load in that case serves as a low pass filter. Never measure the output at no-load condition. Also differentiate the voltage harmonics from the current harmonics.