Abstract: A process for manufacturing tetrahydrofuran, tetrahydropyran and, more generally, cycloether derivatives through the cyclodehydration of 1,4- or 1,5-diols. More specifically, the process of the invention involves (i) the stereoselective cyclodehydration in water of 1,4- or 1,5-diols including at least one chiral tertiary alcohol functional group with retention of the initial chirality, and/or (ii) the cyclodehydration in water of 1,4- or 1,5-diols, said diols being non-miscible with and/or non-soluble in water, into corresponding cycloether derivatives, by bringing the reaction mixture to high temperature water (HTW) conditions and/or by mixing the aqueous reaction mixture with a solid catalyst, such as for example a smectite clay. Also, the use of the process for manufacturing ambrafuran, especially (?)-ambrafuran and other cycloether derivatives.

Abstract: A process for manufacturing tetrahydrofuran, tetrahydropyran and, more generally, cycloether derivatives through the cyclodehydration of 1,4- or 1,5-diols. More specifically, the process of the invention involves (i) the stereoselective cyclodehydration in water of 1,4- or 1,5-diols including at least one chiral tertiary alcohol functional group with retention of the initial chirality, and/or (ii) the cyclodehydration in water of 1,4- or 1,5-diols, said diols being non-miscible with and/or non-soluble in water, into corresponding cycloether derivatives, by bringing the reaction mixture to high temperature water (HTW) conditions and/or by mixing the aqueous reaction mixture with a solid catalyst, such as for example a smectite clay. Also, the use of the process for manufacturing ambrafuran, especially (?)-ambrafuran and other cycloether derivatives.