Enantiomeric Variability of Distaminolyne A. Refinement of ECD and NMR Methods for Determining Optical Purity of 1-Amino-2-Alkanols.

Sample configurations of distaminolyne A (); isolated from the ascidians and , and collected at different sites in New Zealand, were investigated by two methods: Exciton coupled electronic circular dichroism (EC ECD) of the corresponding ,-dibenzoyl derivative ; and chiral reagent derivatization of with ()- and ()-α-methoxyphenylacetic acid (MPA), followed by ¹H-NMR analysis. Configuration and optical purity of (%ee) was found to vary depending on the geographic distribution of ascidian colonies. An improved method for preparing ,-diarenoyl derivatives of was optimized. The EC ECD method was found to be complementary to the MPA-NMR method at different ranges of %ee.