A synthesis reaction that involves oxygen is commonly called combustion.

Here's why:

* Synthesis Reaction: A synthesis reaction is a chemical reaction where two or more reactants combine to form a single, more complex product.

* Oxygen: Oxygen is a highly reactive element that readily participates in chemical reactions.

* Combustion: This is a chemical process that involves the rapid reaction between a substance with an oxidant, usually oxygen, to produce heat and light.

Therefore, when a synthesis reaction involves oxygen, it is specifically classified as combustion.