cyclo {[(6-Amino-6-deoxy-2,3:4,5-di-O-isopropylidene-D-galactonic acid)-(D-Phe)]2}

Determination of the crystal structure of the title compound [systematic name: 9,25-dibenzyl-4,4,15,15,20,20,31,31-octa­methyl-3,5,14,16,19,21,30,32-octa­oxa-8,11,24,27-tetra­aza­penta­cyclo­[27.3.0.02,6.013,17.018,22]dotriacontane-7,10,23,26-tetrone], C42H56N4O12, a cyclic tetra­mer, established the relative stereochemistry of its ten stereogenic C atoms; an inter­esting saddle-like conformation is adopted. There are two mol­ecules in the asymmetric unit. With the exception of the phenyl and isopropyl­idene groups, the mol­ecules are related by a non-crystallographic twofold rotation axis. There are varying degrees of disorder in the isopropyl­idene groups.