Aporphines 65: Chemical, microbial synthesis and characterization by gas chromatography/mass spectrometry of (R)-(−)-10-hydroxy 11-methoxy-N-n-propylnoraporphine, a potential metabolite ofN-n-propylnorapomorphine

The title compound has been synthesized by a multistep sequence from (R)(-)-morphine, and compared with the product obtained by microbial O-demethylation of (R)- and (S)-10,11-dimethoxy-N-n-propylnoraporphine (N-n-propylnorapomorphine dimethyl ether). The comparison was based on an analysis of the trifluoroacetyl derivatives of the microbial products and the synthesized compounds using gas chromatography/mass spectrometry in the electron impact mode. Examination by gas chromatography/electron impact/mass spectrometry of the trifluoroacetyl derivatives of 11-hydroxy-10-methoxyaporphine (apocodeine, 3) and 10-methoxy-11-hydroxyaporphine (isoapocodeine, 5) has revealed their excellent chromatographic resolution, and the preferential loss of the methyl group as in 3 [M-15]+ or the trifluoroacetyl group from the 10-position of the aporphine ring as in 5 [M-97]+. Characteristic fragmentations of these isomeric aporphines were used to confirm their structures and were compared with the spectra of authentic synthetic samples.