Process for the cyclodehydration of diols and use thereof for the manufacturing of ambrafuran and other cycloether derivatives

摘要

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.

主权项

1. A process for the stereoselective synthesis of chiral cycloether derivatives from chiral diols comprising:
(i) stereoselective cyclodehydration in water of 1,4- or 1,5-diols comprising at least one chiral tertiary alcohol functional group with retention of the initial chirality, and/or (ii) 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, said process comprising: bringing a reaction mixture of (i) higher than 3% (w/w) of water and 1,4- or 1,5-diols comprising at least one chiral tertiary alcohol functional group with retention of the initial chirality and/or (ii) water and 1,4- or 1,5-diols, said diols being non-miscible with and/or non-soluble in water, to high temperature water (HTW) conditions with a temperature from 80° C. to 380° C.; and/or mixing a reaction mixture of (i) water and 1,4- or 1,5-diols comprising at least one chiral tertiary alcohol functional group with retention of the initial chirality and/or (ii) water and 1,4- or 1,5-diols, said diols being non-miscible with and/or non-soluble in water with a solid catalyst at a temperature from room temperature up to 380° C.