PRODUCTION OF ALPHA,BETA-CYCLIC UNSATURATED ETHER

PURPOSE:To readily, industrially and advantageously obtain the subject compound useful as a raw material for medicines, etc., in high yield, by simultaneously carrying out catalytic dehydrogenation and dehydration of an alkanediol having OH groups at both terminals using metallic cobalt having a specific crystal structure as a catalyst. CONSTITUTION:An alkanediol, expressed by the formula (R and R are H or lower alkyl; n is 4 or 5) and having 4-5C backbone chain with OH groups at both terminals is reacted in the presence of metallic cobalt having a crystal structure at >=3.0 ratio (B/A) of the area (B) of diffraction peak at 2theta=44.3 deg. to the area (a) of diffraction peak at 2theta=47.6 deg. in powder X-ray diffractometry using CuKalpha radiation at 100-300 deg.C under ordinary pressure to simultaneously carry out catalytic dehydrogenation and dehydration and afford the aimed compound, such as 2,3-dihydrofuran. The afore-mentioned catalyst is obtained by heating, e.g. normally available metallic cobalt having =500 deg.C in an atmosphere of H2 gas.