Hello Dima.
The answer is definitely no! Nooooo!
You should not use your Syrian passport. Using the passport means that you accept to go under the protection of the government that you had originally sought protection from. This will trigger a cessation application by the Minister.
Read here:
https://www.irb-cisr.gc.ca/en/legal-policy/legal-concepts/Pages/RefDef12.aspx
(a) the person has voluntarily reavailed themself of the protection of their country of nationality;
Even though you have the PR, cessation will revoke your status and will trigger a deportation order. You will lose everything you have done!!