Question

1,4-Dioxane is made commercially by the acid-catalyzed condensation of an alcohol.

(a)Show what alcohol will undergo condensation, with loss of water, to give 1,4-dioxane.

(b)Propose a mechanism for this reaction

Short answer

(A) Reaction between ethylene glycol in presence of acid to give dioxane

(B) Mechanism for the above reaction is

Step-by-step solution

Step 1: 

Dioxanesare ethers with two oxygen atoms in a six-membered ring. The most useddioxane is the one with the two oxygenatoms in a 1,4-relationship (1,4-dioxane). Dioxane usedas a polar solvent for organic reactions.

Step 2

In mechanism first step is protonation and removal of a water molecule from ethylene glycol. In the second step another ethylene glycol attacks this protonated molecule. In the last step removal of a water molecule to give 1,4-dioxane.