Structural discrimination from in situ measurement of D and D residual dipolar coupling constants.

A fast residual dipolar coupling constant-assisted strategy involving the simultaneous determination of scalar and total coupling constants from a single J / J -resolved NMR spectrum is reported. It is shown that the concerted use of the directly measured D (for all CH multiplicities) and D residual dipolar couplings allows an on-the-fly assignment of diastereotopic CH protons, as well as of an efficient discrimination between diastereoisomeric structures of strychnine which contains six stereocenters. Copyright © 2017 John Wiley & Sons, Ltd.