Abietane diterpenoids from the cones of larix kaempferi

Three new abietane-type diterpenes, 7alpha,15-dihydroxyabieta-8,11, 13-trien-18-al (1); 15,18-dihydroxyabieta-8,11,13-trien-7-one (2); and 18-nor-4,15-dihydroxyabieta-8,11,13-trien-7-one (3), were isolated from the cones of Larix kaempferi, together with three known diterpenes, abieta-8,11,13-trien-18-yl succinate, 16-nor-15-oxoabieta-8,11,13-trien-18-oic acid, and 7beta-hydroxyabieta-8,11,13-trien-18-oic acid. The structures of 1-3 were determined on the basis of chemical and spectral evidence.