126-54-5 2,4,8,10-Tetraoxaspiro[5.5]undecane 5,5'-Spirobi-1,3-dioxane 5,5'-Spirobi-m-dioxane Formaldehyde, cyclic diacetal with pentaerythritol NSC49146 Pentaerythritol bisformal Pentaerythritol cyclic diformal Pentaerythritol diformal Pentaerythritol, bis(cyclic acetal) with formaldehyde- Pentaerythritol, dimethylene-