2,2',3,3'-Tetra-O-benzyl-alpha,alpha-trehalose (III) was prepared by condensation of trehalose (I) with benzaldehyde, followed by alkylation of the resulting bisbenzylidene derivative (II) with benzyl chloride and then acid hydrolysis of the benzylidene ketal. Acylation of (III) with octanoyl chloride (IV) in the presence of pyridine provided diester (V). Finally, catalytic hydrogenolysis of the benzyl protecting groups yielded the title compound.