3,3,5,5-Tetramethyl-l,2,4,5-tetroxane

X-ray studies have shown that 3,3,6,6-tetramethyl-l,2,4,5-tetrathiane exists in the twist conformation 164 in the solid state. According to ab initio calculations at the HF/6-31G, MP2/6-31G, and B3LYP/6-31G levels the twist conformation 164 is 4 kj mol-1 more stable than the chair conformation 165 and the calculated strain energy for twist-to-chair conversion is 61.1 kj mol-1 (Scheme 9). The chair conformation of the parent 1,2,4,5-tetrathiane was calculated to be 10.7 kj mol-1 more stable than the twist form <2004PS2015>. X-ray crystallography has confirmed that in the solid state 3,3,6,6-tetramethyl-l,2,4,5-tetroxane adopts a chair conformation 166 . 

The rates for the thermolysis of cyclic peroxides are also only slightly solvent-dependent. For example, the first-order decomposition of acetone cyclic diperoxide (3,3,6,6-tetramethyl-l,2,4,5-tetroxane) increases only 21-fold on going from n-octane to acetic acid as solvent, corresponding to homolytic 0-0 bond rupture [824],... 

Gelalcha, F.G., Schulze, B., Lonnecke, P. 3,3,6,6-Tetramethyl-l,2,4,5-tetroxane A twinned crystal structure. Acta Crystallogr. C Cryst. Struct Commun. C60, ol80-ol82 (2004)... 

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