Phenyltropanes (PTs) were originally developed to reduce cocaine addiction and dependency.[2][3] In general these compounds act as inhibitors of the plasmalemmalmonoaminereuptaketransporters. This research has spanned beyond the last couple decades, and has picked up its pace in recent times, creating numerous phenyltropanes as research into cocaine analogues garners interest to treat addiction.
^"The methyl has to be at the other O, and trans" does not put the methyl group somewhere else in the molecule: the ester group is oriented more outward leading to a less congestion around the methyl group. A second benefit to this orientation is freeing the nitrogen atom to form hydrogen bonding or even accept a proton to form a better soluble positive charged ion.
^Runyon, S. P.; Carroll, F. I. (2006). "Dopamine transporter ligands: recent developments and therapeutic potential". Current Topics in Medicinal Chemistry. 6 (17): 1825–1843. doi:10.2174/156802606778249775. ISSN1568-0266. PMID17017960.