1,1,3,3-Tetramethyldisiloxane (TMDS) has been developed as an excellent dual-purposereductant for the highly regioselectiveringcleavage of various hexopyranosyl 4,6-O-acetals with Cu(OTf)2 or AlCl3 to afford the corresponding primary and secondary ethers. Its application to the concise synthesis of carbohydrate-based surfactants is highlighted.