A gemini neoglycolipid was synthetised from pentaerythritol as the central building block to which were coupled two lipid moieties (C16H33 alkyl chains). The subsequent glycosylation reaction with two carbohydrate units (beta-D-GlcNAc) was achieved in acceptable yields which were, nevertheless, much lower than those obtained with the single-chain homologous derivatives. The behaviour of this neoglycolipid in monolayer was studied in details after spreading at an air/water interface. These molecules exhibit transition phases when the monolayer is compressed, revealing a similar behaviour to that of phospholipids. The behaviour of neoglycolipid 1 suggests a peculiar conformation at the air/water interface. This supramolecular arrangement might be taken as a model for molecular recognition of glycolipids in organized systems. (C) 1997 Elsevier Science Ireland Ltd.