Stereoselective synthesis of β-naltrexol, β-nalaxol, β-naloxamine, β-naltrexamine and related compounds by the application of the Mitsunobu reaction

Article abstract of DOI:10.1016/S0040-4020(01)85541-1

As a continuation of our work, aimed at adopting the Mitsonobu reaction in the morphine series, a few representatives of dihydroisocodeines and dihydroisomorphines and their 14β-hydroxy analogues were prepared. p-Nitrobenzoic acid was used as carboxylic acid and the prepared esters were cleaved to obtain the title compounds. Using phthalimide as acidic component several new 6β-phthalimidodihydromorphine and dihydrocodeine derivatives and their 14β-hydroxy analogues have been synthesized. Cleavage of the phthalimido derivatives with hydrazine hydrate afforded the corresponding 6β-amino derivatives.