1,4-dioxane
= 1,4-dioxane
<1,4-dioxane> is a six-membered cyclic <ether> with oxygen atoms at positions one and four, formula $\mathrm{C_4H_8O_2}$. It can adopt chair-like conformations analogous to those of cyclohexane.
Its ether oxygens can accept hydrogen bonds and coordinate suitable solutes. The positions of those oxygens distinguish it from other dioxane isomers, so the numerical prefix is part of its chemical identity.