We have designed and synthesized a highly lipophilic boronic acid (11) with a molecular shape that makes it much more effective at carrying sugars through organic membranes than a previously used steroidal boronic acid. The corresponding diboronic acid (12) was also found to transport fructose ahead of glucose with a very high selectivity (7.6:1.0). Modeling suggests that 12 is able to carry two fructose molecules at once in a complex stabilized through hydrogen bonding and ion pairing.

The title compound, C18H18B2O6, was formed by the reaction between phenyl­boronic acid and d‐glucose. The structure is analogous to those of d‐glucoboronates previously prepared and characterized by NMR. In the crystal structure, mol­ecules are linked into one‐dimensional chains along [100] via O—H⋯O hydrogen bonds [O⋯O = 2.8283 (17) Å].