Abstract
15α-Hydroxy-ent-kaur-16-en-19-oic acid (IX) (=grandifloric acid) and a new diterpene acid, 17-hydroxy-ent-kaur-15-en-19-oic acid (X) were isolated as the minor constituents from the roots of Aralia cordata THUNB. The final identification of IX and the structural elucidation of X were accomplished by preparation of IX and the methyl ester of X (XI) from methyl ent-kaurenoate (XII) by means of the double bond isomerization and the dye-sensitized photooxidation.
