There are currently a few different PHs/designer steroids that are on the market that fall into what you are asking about. They are not the same as the old 19-norandrostenedione (aka 19-norandro or norandro) that you could once buy from GNC, which was actually a pro-steroid to nandrolone. I believe it also had anabolic and androgenic properties before conversion. You also mentioned 4-AD (aka 4-androstenedione or simply, andro). Again, this is a pro-steroid to test.
Advanced Muscle Science has a few products out that are said to be two steps away from converting into these old pro-steroids that you are asking about. These are still currently legal, but there's not a ton of user feedback on them for some reason:
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Some of these other "19-nor" products are also referred to as the TREN products. I hate it when people refer to a particual steroid as "19-nor" because it can be very misleading. Some people say 19-nor and really mean 19-Norandrosta 4,9 diene 3,17 dione, which is obviously a particular steroid. 19-Norandrosta 4,9 diene 3,17 dione is the same thing as Estra 4,9 diene 3,17 dione. I believe this is another pro-steroid and is the precursor to dienelone:
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That should be enough to get you started...
EDIT: This might help a little...meh, maybe not, lol -
http://anabolicminds.com/forum/steroids/79658-nomenclature-dummies.html