The title compound, C(23)H(30)O(9), has an approximate T-shape with the tert-butyl ester groups lying either side of the benzene ring. The acetyl group is almost perpendicular to the benzene ring to which it is connected [C-C-O-C torsion angle = -106.7 (3)°]. The conformation about the C=C double bond [1.331 (4) Å] is E. Linear supra-molecular chains along the a axis mediated by hy-droxy-carbonyl O-H⋯O hydrogen bonds feature in the crystal packing. The same H atom is also involved in an intra-molecular O-H⋯O inter-action.