Title
Enantiomeric Variability of Distaminolyne A. Refinement of ECD and NMR Methods for Determining Optical Purity of 1-Amino-2-Alkanols
Author
A. Norrie Pearce, Brent R. Copp, Tadeusz F. Molinski
Year
2019
Journal
Molecules
Abstract
Sample configurations of distaminolyne A (1a); isolated from the ascidians Pseudodistoma opacum and P. cereum, and collected at different sites in New Zealand, were investigated by two methods: Exciton coupled electronic circular dichroism (EC ECD) of the corresponding N,O-dibenzoyl derivative 1b; and chiral reagent derivatization of 1a with (S)- and (R)-α-methoxyphenylacetic acid (MPA), followed by 1H-NMR analysis. Configuration and optical purity of 1a(%ee) was found to vary depending on the geographic distribution of ascidian colonies. An improved method for preparing N,O-diarenoyl derivatives of 1a was optimized. The EC ECD method was found to be complementary to the MPA-NMR method at different ranges of %ee.
Full Article
Instrument
J-810
Keywords
Circular dichroism, Cotton effect, Stereochemistry, Natural products, Absolute configuration, Pharmaceutical