3,3,6,6-Tetramethyl-1,2,4,5-tetroxane: a twinned crystal structure.

The title compound, C6H12O4, also known as dimeric acetone peroxide, Me2(C2O4)Me2, has crystallographically imposed inversion symmetry and adopts a chair conformation in the solid state. This structure contrasts with that of the sulfur homologue Me2(C2S4)Me2, which has crystallographically imposed -4 symmetry and crystallizes in a twist-boat conformation. Crystals of the title compound are twinned along the reciprocal c* axis.