Theoratically you can make a transformerless power supply, you will have to design high power charge pump voltage doublers/multipliers, then have a sineweighted full bridge to get the sine.
but the efficiancy you get may be less than 10-15% and will not be practicle
Generally transformer-less also means one without the use of low frequency Iron core based transformer, instead people us a high frequency transformer to boost the dc voltage to high voltage Dc and use a bridge and filter to convert it to AC