From 1,2-dialkoxyalkanes to 1,4-dioxanes: a transformation mediated by NbCl5 via multiple C-O bond cleavage at room temperature

The formation of 1,4-dioxanes and alkyl chlorides from the reactions of polyethers (dme, diglyme, 1,2-diethoxyethane, 1,2-dimethoxypropane) with NbCl5 at room temperature is described; as far as dme is concerned, the reaction mainly occurs in two steps, consisting of (i) cleavage of one O–CH3 bond, followed by (ii) cleavage of the second O–CH3 bond and one of the two O–CH2 linkages. The characterization of intermediate complexes and the isolation of NbOCl3(dme) are reported.