Abstract
Acetylation and subsequent oxidation of the organoborane intermediate obtained from hydroboration of isoneopine (III) gave (-)-3-methoxy-6β-acetoxy-8α-hydroxy-4, 5α-epoxy-N-methylisomorphinan (IV). Hydroboration of isoneopine-(N-n-butyl)-carbamate (XIV) gave the 6β-(N-n-butyl)-carbamoyloxy-8α-hydroxy derivative (XV). (-)-3-Methoxy-6β-hydroxy-4, 5α-epoxy-Δ7-N-methylisomorphinan (XIII, B/C trans-isocodeine) was synthesized from either IV or XV via elimination of the respective 8α-tosyloxy derivatives (VI and XVI). XIII was also obtained by solvolysis of (+)-3-methoxy-6α-tosyloxy-4, 5α-epoxy-Δ7-N-methylisomorphinan (XIX). Demethylation of XIII gave the title compound (XXII).
