Process for preparing 1,5-dioxepan-2-ones from tetrahydro- 4H-pyran-4-ones

摘要

This publication describes a novel process for preparing ether lactones, which are per se previously known, of the general formula I: IMAGE in which R1-R8 in each case represents hydrogen or methyl, with, however, at least either both R1 and R2 or both R7 and R8 always being hydrogen. That which is novel in connection with the process is that the starting compound is a cyclic compound of the general formula II: IMAGE in which R1-R8 have the previously mentioned meanings, and this compound is subjected to ring expansion in a single step, preferably using an organic peracid, in order to form the desired ether lactone.