A total synthesis of isoliensinine

Abstract

Cyclisation of the amide (VI) prepared by condensation of 4-methoxyphenylacetic acid and 4-benzyloxy-3-methoxyphenethylamine, gave the 3,4-dihydroisoquinoline (VII), the methiodide of which, on reduction, afforded the tetrahydroisoquinoline (IX). Ullmann reaction between (±)-(X) and (±)-(XI) afforded a mixture of the diastereoisomeric racemates of OO-dibenzylisoliensinine (V), the debenzylation of which gave a mixture of diastereoisomeric racemates of isoliensinine (II). Finally, total synthesis of optical active isoliensinine has been achieved.