L. Toma, G. Cignarella, D. Barlocco
1992
Citations
0
Influential Citations
11
Citations
Journal
Tetrahedron
Abstract
Abstract 3-Trans-cinnanyl-8-propionyl-3,8-diazabicyclo[3,2,1]octane 1 , its monocyclic analog 4-trans-cinnamyl-1-propionyl-cis-2,6-dimethylpiperazine 2 and their isomers having the nitrogen sustituents exchanged, 3 and 4 , have been submitted to conformational analysis by molecular mechanics and 1 H NMR spectroscopy. The results of molecular modeling indicate that, while the monocyclic compound 2 has a preferred conformation very similar to the corresponding bicyclic compound 1 , compound 4 is quite different with respect to 3 ; it is the only compound with equatorially oriented substituents on the carbon atoms of the hexacyclic ring. This feature could explain the low affinity of 4 towards μ receptors, as compared with the high affinity of 1 – 3 .