You Do Need power plug adapter while traveling from Luxembourg to Syria.

Here is Why You Need An Adapter

The outlet and plug type used in Syria are C, E and L and in Luxembourg are C and F. This is how they look like.

Luxembourg

In Luxembourg, outlets of type C and F are in use.

Type C

Type F

Syria

In Syria, outlets of type C, E and L are in use.

Type C

Type E

Type L