18-nor-Abietatrienes from the Cones of Larix kaempferi

Two novel norditerpenediols, 18-nor-abieta-8,11,13-triene-4,15-diol (1) and 18-nor-abieta-8,11,13-triene-4,7alpha-diol (2), were isolated from the cones of Larix kaempferi, together with two known diterpenes, abieta-8,11,13-triene-15,18-diol and abieta-8,11,13-triene-7alpha,18-diol. The structures of 1 and 2 were determined on the basis of chemical and spectral evidence.