Tropinone based fentanyls

[Cyrax]

Can someone help me out on this one: How potent is the tropinone based fentanyl analog?  What is the ED50? How potent is it, compared to fentanyl?

I guess if one would use phenethylamine instead of methylamine in the Robinson synthesis of tropinone, one would get a usefull tropinone based fentanyl precursor.  Am I right?

[Rhodium]

Yes to your last question.