Download full text in PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... 1,4 and 1,5-diols heated with 0.3 equivalent of HMPA undergo cyclodehydration leading to tetrahydrofurans and tetrahydropyrans. ... Ce travail, réalisé au laboratoire de Chimie Biologique de l'INSA de Lyon a bénéficié d'une aide du CNRS (UA 04 495) et de l'INSERM (U 205).