Synthesis and structure of 2,4,6-tri-cyclo-butyl-1,3,5-trioxane

The synthesis and structure of 2,4,6,-tri-cyclo-butyl-1,3,5-trioxane, C₁₅H₂₄O₃ 1, is described. It was formed in 39% yield during the work-up of the Swern oxidation of cyclo-butyl-methanol and may serve as a stable precursor of the cyclo-butane carbaldehyde. The mol-ecule of 1 occupies a special position (3.m) located at the center of its 1,3,5-trioxane ring. The latter is in a chair conformation, with the symmetry-independent O and C atoms deviating by 0.651 (4) Å from the least-squares plane of the other atoms of the trioxane ring. All three cyclo-butane substituents, which have a butterfly conformation with an angle between the two planes of 25.7 (3)°, are in the cis conformation relative to the 1,3,5-trioxane ring. Inter-molecular C-H⋯O inter-actions between the 1,3,5-trioxane rings consolidate the crystal structure, forming stacks along the c-axis direction. The crystal studied was refined a as a racemic twin.