Dehydration of 1,5-pentanediol was investigated over ZrO2 and Yb2O3 catalysts at 300-450 degrees C. 1,5-Pentanediol was converted into 4-penten-1-ol together with tetrahydropyran over monoclinic ZrO2 at temperatures <400 degrees C, and the selectivity to 4-penten-1-ol exceeded 50 mol%. Modification of ZrO2 with Li ions increased the selectivity to 4-buten-1-ol up to 70 mol%. Yb2O3 also effectively worked as a catalyst in the dehydration of 1,5-pentanediol into 4-buten-1-ol at temperatures <425 degrees C. Especially, Yb2O3 with cubic structure showed higher than 75 mol% selectivity to 4-penten-1-ol. (c) 2007 Elsevier B.V. All rights reserved.