Electric field effects in ¹³C NMR of some quaternary morphinan derivatives

Abstract

Table 3 . ' H NMR of diasteredsomem 5a and 5b HC HY HE HZ HA Hx threo I I I I I I CCI c-c-c--c-c-c-cI ' -1 I I I I I H, CI Hp CI H, CI 5a EA 88 ax Ec % SY EE EF 82 2.661 2.546 5.995 3.328 3.175 4.380 2.434 2.434 4.350 J O J ( W JWB) J O J(Bn J(CW J(DW J(CD) J(EF) 9.32 3.64 14.63 2.80 10.63 5.93 4.27 15.7 0 J(W) J ( Z 3 J(R) J(W) 6.84 6.84 6.84 6.84 HC b HE HZ HA HX erythro

Voltammetric Oxidation of Drugs of Abuse I. Morphine and Metabolites

“…After preparative TLC the major isomer was isolated (silica gel; chloroform/ methanol/diethylamine (8 : 1.5 : 0.5)). The analytical data of the compound were similar to those found in the literature [16,17,19,20].…”

Investigation of the acid/base behaviour of the opium alkaloid thebaine in LC-ESI-MS mobile phase by NMR spectroscopy

“…At more remote locations within the molecule, the chemical shift differences between the analogous H atoms on the epimers are less profound and the two separate signals cannot always be observed by simple inspection of the 1D 1 H NMR. However, assignments of signals on NMR spectra were made in reference to previously published analyses [10][11][12][13] and use 2D HH and HC COSY to support these conclusions. The 1 H NMR spectrum of thebaine in an 80 : 20 v/v D 2 O/CD 3 CN solvent mix containing 1% CD 3 COOD (figure 3a) indicates the presence of two epimeric forms in an approximate ratio of 58 : 42.…”

“…[ 10 ] reported the 13 C spectra for morphine alkaloids thebaine and sinomenine. In 1984, Theuns et al [ 11 , 12 ] analysed the structure of thebaine using both 13 C and 1 H NMR and most recently Caldwell et al . [ 13 ] reported the configurational analysis of thebaine and codeine using 13 C and 1 H NMR in 1996.…”

“…In 1975, Terui et al [10] reported the 13 C spectra for morphine alkaloids thebaine and sinomenine. In 1984, Theuns et al [11,12] analysed the structure of thebaine using both 13 C and 1 H NMR and most recently Caldwell et al [13] reported the configurational analysis of thebaine and codeine using 13 C and 1 H NMR in 1996. In this article, we report experiments which were performed to analyse structural behaviour in a range of solvents which replicate the changes in mobile phase composition encountered by the thebaine analyte during analysis by LC-ESI-MS.…”