This seems an odd request. I've never heard of a potential employer requesting a syllabus. A syllabus is specific to a single class. Did you mention that you took a specific class and now they are wondering what you did in that class? That would make sense. However, potential employers will generally ask for for a transcript (a list of all the courses you took and the grades you obtained). Hm, now I'm curious hahah

A course syllabus is a course "programa". It shows the books read in the course and their citations, a schedule of the course, and rules and policies of the teacher. What is the internship you're applying for? Do you have to create a course for it?