Patent ID: 8791307

Claim:
A process for producing α,β-unsaturated ethers, comprising pyrolyzing an acetal in a gas phase in the presence of a catalyst and a compound having at least one hydrogen atom capable of hydrogen bonding, wherein the compound having at least one hydrogen atom capable of hydrogen bonding is water and/or a carboxylic acid; wherein the process comprises: a step of supplying the water and optionally the carboxylic acid to the acetal to obtain an acetal solution, wherein the concentration of the water relative to the acetal is 40 to 5000 ppm by weight when supplying the water, and the concentration of the carboxylic acid relative to the acetal is 5 to 5000 ppm by weight when supplying the carboxylic acid, and a step of feeding the acetal solution to a reactor with the catalyst; wherein the catalyst contains an apatite represented by Formula (1) below: (M) 5-y (HZO 4 ) y (ZO 4 ) 3-y (X) 1-y (1) wherein M is at least one selected from the group consisting of Mg, Ca, Sr, Ba, Pb, Mn and Cd; Z is at least one selected from the group consisting of P, As and Sb; X is at least one selected from the group consisting of OH, F, Cl, Br, I and At; and 0≦y<1; wherein the temperature in the gas-phase pyrolysis of the acetal is in the range of 150 to 400° C.