Absolute Configuration of the Polyketide Natural Product (−)-Enterocin

The absolute configuration of the polyketide natural
product (−)-enterocin
was established by two independent approaches. In the first approach,
synthetic enterocin with a defined configuration was compared to the
natural product. While identical in all scalar properties, the compound
displayed an opposite specific rotation and a different chiral HPLC
retention time when compared with (−)-enterocin. In a second
approach, the vibrational circular dichroism (VCD) of the natural
product was measured and shown to be opposite to the calculated VCD
of its enantiomer.