Flight home from HAN-PVG-PEK-YYZ staying less than 72hr either city?

We plan to fly from Toronto to Hong Kong November 21, leaving Hong Kong November 26 to fly to Vietnam (no Visa required I believe). We plan to Fly home to Canada Via Shanghai, so we can visit a friend for a day or so, but would also like visit Beijing. If we were to book our return flight from Vietnam to Toronto via Shanghai and Beijing (HAN-PVG-PEK-YYZ) landing in Shanghai say December 1, leaving Shanghai to Beijing December 3, leaving Beijing to Toronto December 5. Can we take advantage of the 72 HR free transit doing this, being that we would not be spending more than 72hr in either Shanghai or Beijing?