Structure of (−)-7α-acetyl-4,5α-epoxy-3-methoxy-N-methyl-6,14-ethenoisomorphinan, C22H25NO3

NMR Analysis of a Series of 6,14‐Ethenomorphinan Derivatives as PET Precursors and Reference Substances**

“…Three minimum‐energy conformers were chosen semiempirically using the criteria of 10 kJ/mol as a cut‐off value for the lowest energy conformers. These conformers differ in the proper positions of the three substituents of C20 and the orientation of N 17 ‐CH 3 group, while the conformation of the 6,14‐endoethenomorphinan ring system is practically the same thus reproducing well the X‐ray structure of similar derivatives [58,59] . The optimized geometry of TDPEO ( 16 d ) obtained with DFT at the B3LYP/6‐31G(d) level of theory (presented from the direction of the ring E and the reverse direction denoting the C20‐OH‐C6‐O distance) is depicted in Supporting Information, (Section 6, Figure CP2, page 40).…”

“…These conformers differ in the proper positions of the three substituents of C20 and the orientation of N 17 -CH 3 group, while the conformation of the 6,14-endoethenomorphinan ring system is practically the same thus reproducing well the X-ray structure of similar derivatives. [58,59] The optimized geometry of TDPEO (16 d) obtained with DFT at the B3LYP/6-31G(d) level of theory (presented from the direction of the ring E and the reverse direction denoting the C20-OH-C6-O distance) is depicted in Supporting Information, (Section 6, Figure CP2, page 40). The three potential structures were refined by geometry optimizations with DFT at B3LYP/6-31G(d) level resulted in one optimized geometry (Supporting Information, Figure CP2, page 40) in terms of steric energies.…”

(5R,6R,7R,9R,13R,14S)-21-Cyclopropylmethyl-6,14-endo-ethano-2′,3′,4′,5′,7,8-hexahydro-4′,4′,5′,5′-tetramethylfurano[2′,3′6,7]normorphide hydrochloride methanol solvate

“…Demethoxy-buprenorphine possesses a typical opiate T shape ( Fig. 1), similar to that of buprenorphine (Kratochvíl et al, 1994) and related morphinanes with a 6,14-etheno bridge (Van den Hende & Nelson, 1967;Van Koningsveld et al, 1984;Michel et al, 1988;Michel & Michel-Dewez, 1990;Hušá k et al, 1993;Bulej et al, 1993). Benzene ring A (atoms C1-C4/C12/ C11) and atom O1 are almost planar.…”