摘要：By successive oxidation with selenium dioxide and sodium dichromate followed by introdution of a hydroxymethylene group, a partial structure -C=C-CH2-CH2- was given for a diterpenic acid C20H30O2 (II) which was isolated from the fruits of Japanese juniper. Further, as the acid (II) gave tetrahydro-7-isodextropimaric acid after consumption of two moles of hydrogen, the structure of (II) was concluded to be represented by △13, 14-7-isodextropimaric acid. The structure of a doubly unsaturated compound obtainable from a hydroxymethyl ester (VI), an oxidation product of (V), was proposed to be △5, 13 : 9, 14-7-isodextropimaric acid.
