New 2/2-type surfactants via anomeric O-alkylation of mannofuranose

New 2/2-type surfactants were synthetized from 1,2-di-O-alkyl-4-O-benzyl-l-threitols and 1,3-di-O-alkyl-4-O-benzyl-d-threitols. Their transformation into trifluoromethanesulfonates and then reaction with 2,3:5,6-di-O-isopropylidene-d-mannofuranose gave, via anomeric O-alkylation, predominantly β-d-mannofuranosides of erythritol. Hydrogenolytic O-debenzylation furnished the 4-O-deprotected derivatives which, on reaction with sulfur trioxide-trimethylamine and then hydrolytic removal of the O-isopropylidene groups, afforded 2/2-type surfactants having a mannofuranose and a sulfate residue as head groups. The 4-O-deprotected derivatives were also transformed into the corresponding 4-tosylates and the 4-iodides as alkylating agents. Their reaction with tetraethylene glycol, diethyl malonate, and diethyl iminodiacetate and then removal of the protective groups furnished 2/2-type surfactants having a mannofuranose residue and a tetraethylene glycol, or a malonate, or an iminodiacetate residue, respectively, as head groups. Surface tension and critical micelle concentration measurements with these compounds exhibited interesting amphiphilic properties. © 1997 Elsevier Science Ltd.