Flying from Bangkok to Shanghai then to Yangon(Myanmar) but with a step over in Bangkok

Hello,
I'm going to Shanghai for the week-end coming from Bangkok. Then I have a flight from Shanghai to Myanmar with a step over in Bangkok. I've seen that I can not get the 72 hours visa if I'm flying from one country to shanghai and then to the same country. What if it's a step-over like in my case? Is it still ok as my final destination Is Rangun?
Thanks