The title compound, C(27)H(34)O(5), a beyerane-type diterpenoid prepared by peroxidation and benzoyl-ation of isosteviol, contains a fused six-membered ring system. The O atoms of the benzoic ester and the lactone are disordered with occupancy ratios of 0.6 (4):0.4 (4) and 0.6 (2):0.4 (2), respectively. Three cyclo-hexane rings have chair conformations, whereas the remaining lactone ring adopts a half-chair conformation.