Synthesis and structure of tetraols with convergent and divergent arrays of hydroxy groups

As hydrogen-bonding hosts with a partially flexible framework, two types of tetrahydroxy compounds with respectively convergent and divergent arrays of hydroxy groups were prepared. The structures of the tetraol with a diethyleneoxy bridge (1a), and that with a m-phenylenedioxy bridge (syn-13a and anti-13b) were determined by X-ray crystallographic studies. syn-13a forms an inclusion crystal with 1,4-dioxane, one molecule of which is bound in the cleft of syn-13a and the other in the intermolecular cavity.