The title compound, C(19)H(25)NO(6), is a Z diastereomer in which the phenyl ring of the 3-benzyl-oxime substituent and the 5,6-O-isopropyl-idene acetal are both located on the Si-face of the C=N double bond. Inter-molecular C-H⋯O inter-actions result in helical chains along the b axis of the monoclinic unit cell.