10-Acetoxy-2-hydroxy-1,2,6a,6b,9,9,12a-heptamethyl-1,3,4,5,6,6a,6b,7,8 ,8a,9,10,11,12,12a,12b,13,14b-octadecahydro-2H-picene-4a-carboxylic ac id, methyl ester