Organic synthesis problems
Search for the latest IChO tests and preparatory problems. You can find quite a few interesting problems.

Here are some tests:
http://www.iuventa.sk/files/documents/5_icho/past%20competition%20tasks/volume3-icho41-45.pdf

http://icho2013.chem.msu.ru/materials/Preparatory_problems_IChO_2013.pdf (problems 18-21)

http://icho2014.hus.edu.vn/Preparatory-Problems/0001/01/Preparatory-Problems-224.html (problems 18-26)