In the structure of the title compound, C17H25NO9S2, the bond lengths in the C-S-C moiety are almost equal at 1.7959 (8) and 1.7877 (9) Å, with a shorter formally double C-S bond of 1.6698 (9) Å at the other sulfur atom. The eight-atom sequence O3-C3-C2-C1-S... ...