A simple synthesis of hexakis(6-O-carboxymethyl-2,3-di-O-methyl) cyclomaltohexaose and heptakis(6-O-carboxymethyl-2,3-di-O-methyl) cyclomaltoheptaose

Hexakis(2,3-di-O-methyl)cyclomaltohexaose 1a and heptakis(2,3-di-O-methyl)cyclomaltoheptaose 1b were reacted with ethyl diazoacetate to give hexakis(6-O-ethoxycarbonylmethyl-2,3-di-O-methyl)cyclomaltohexaose2a and heptakis(6-O-ethoxycarbonylmethyl-2,3-di-O-methyl)cyclomaltoheptaose2b. Subsequent alkaline hydrolysis of 2a,b gave the title compounds.