Thionium analogs of the opiates levorphanol and isolevorphanol: synthesis of the 17-deaza-17-thia isosteres (sulforphanol and isosulforphanol)

The total synthesis of the position-17 sulfur analogs of the perchlorate salts of the morphinans, (±)-levorphanol and (±)-isolevorphanol via4a-(2-aminoethyl)-1,2,3,4,4a,9-hexahydro-6-methoxyphenanthrene, a key intermediate in the synthesis of butorphanol (4), is described. 2D-Correlation and heterocorrelation nuclear magnetic resonance spectroscopy confirmed the configurational relationship of the isosteres.