Abstract
Following structural determination of insulanoline (I), isolated from the rhizome of Cyclea insularis (MAKINO) DIELS together with norcycleanine, examinations were made on the latter base. Cleavage reaction of O-ethylnorcycleanine (V) with sodium in liquid ammonia afforded, as the bisected phenolic bases, l-armepavine (VI) and a base identified as l-1-(4-hydroxybenzyl)-2-methyl-6-methoxy-7-ethoxy-1, 2, 3, 4-tetrahydroisoquinoline (VII). This has confirmed that the structure of norcycleanine would be represented by the formula (III).
