Always attempt the problem first. Organic chemistry is about spatial reasoning; you can't learn that by looking at a solution.
If you're using GDZ for these specific topics, pay extra attention, as they are common "trap" areas on exams:
Use the answers to find where your logic failed. Did you miss a functional group? Did you forget the IUPAC naming rules? Essential Topics to Double-Check
Unlike standard textbooks, Nifantyev’s approach is rigorous. It covers:
Understanding why a reaction happens, not just the result.
Нифантьев, Эдуард Евгеньевич - Википедия