(2S,2’S,4R,5S,5’R)-2,2’-Di-tert-butyl-4-hydroxy-5,5’-dimethyl-4,5’-bi(1,3-dioxolanyl)-4’-one

The product formed by base-induced dimerisation of (2S,5S)-2-tert-butyl-5-methyl-1,3-dioxolan-4-one is shown by X-ray diffraction to be the title compound and not the isomeric fused-ring 1,3-dioxolane/1,3-dioxane-4-one structure proposed by previous researchers. The analogous compound derived from (2S,5S)-5-benzyl-2-tert-butyl-1,3-dioxolan-4-one has also been obtained and characterised.