The Configuration of Distaminolyne A is S: Quantitative Evaluation of Exciton Coupling Circular Dichroism of N,O- Bis-arenoyl-1-amino-2-alkanols

The 2S configuration of the marine natural product distaminolyne A was recently disputed based upon total synthesis, yet paradoxically supported by a second independent total synthesis from a different research group. We now verify the 2S configuration of distaminolyne A by extensive chiroptical studies and support the veracity of the EC ECD method originally used to prove it. The origin of the apparent paradox appears to lie in the limits of precision of polarimetry in the context of weakly rotatory molecules, which strikes a cautionary note on the reliability of “reassignment” of natural product configurations based solely on specific rotation.