Tetra-nor-labda-8(17)-en-12-oic acid methyl ester

(12RS)-12-hydroxy-14,15,16-trinorlabd-8(17)-en-13-oic acid

(4aS,8aS)-3,4,4aα,5,6,7,8,8aβ-octahydro-5,5,8aβ-trimethyl-1-methylidene-2(1H)-naphthalenone

8-oxo-14,15,16,17-tetranorlabdan-13-oic acid