trifluoro-methanesulfonic acid 1-benzyloxymethyl-2-(tert-butyl-dimethyl-silanyloxy)-7,10-dimethoxy-1,4a,6a,11b-tetramethyl-2,3,4,4a,4b,5,6,6a,11,11a,11b,12,13,13a-tetradecahydro-1H-indeno[2,1-a]phenanthren-9-yl ester