PURPOSE: To obtain a new aldohexose nomo-branched alkyl ether having excellent moisture retaining power and emulsifying power, useful as a surfactant, a raw material for a medicine such as an antitumor agent, a raw material for a cosmetic. etc.

CONSTITUTION: An aldohexose mono-branched alkyl ether compound of formula I (any one of R of two Rs is a 3-24C branched alkyl group and the other is H) (e.g. 3-O-methyl-branched isostearyl-D-glucopyranose) has excellent moisture retaining power and emulsifying power and is useful as a surfactant, a raw material for a medicine such as an antitumor agent, a raw material for a cosmetic, etc. The compound is obtained by treating glucose, etc., with an excessive amount of acetone to give 1,2;5,6-di-O-isopropylidene-D-glucofuranose of formula II, reacting the compound with an etherifying agent in the presence of an alkali substance and a quaternary onium salt and hydrolyzing the reaction product.