Studies on the syntheses of heterocyclic compounds. Part CCC. Syntheses of salutaridine, sinoacutine, and thebaine. Formal total syntheses of morphine and sinomenine
Abstract
The diazotisation of (±)-1-(2-amino-3-benzyloxy-4-methoxybenzyl)-1,2,3,4-tetrahydro-6,7-dimethoxy-2-methylisoquinoline (VIII) followed by the thermal decomposition of the resulting diazonium salt, gave (±)-salutaridine (II)[or (±)-sinoacutine], which was converted into (±)-thebaine (III). The 2-aminobenzylisoquinoline (VIII) was resolved, and the (–)- and (+)-enantiomers (VIIIa and b) were used for the syntheses of salutaridine (IIa), sinoacutine (IIb), and thebaine (IIIa) and its antipode (IIIb). This work also constitutes the fifth total synthesis of morphine (I).