True, but they are related to the same problem you are trying to solve, so it is best to keep the information together for people who might be able to help you without speculating (like I did when I first observed this question and decided to wait...).
The closest thing to this is that you can configure login modules for the JAVA stack in SAP to point the UME to the AD via LDAP for initial authentication. That opens the door for reuse of the authentication tokens and system trust chains to access ABAP systems as well and even generate SAPGui sessions. Not a very modern approach, and not really SSO either, but for the end user it looks and feels the same.
So the question is: do you have a SAP Portal or a SAP IDM system?
Cheers,
Julius