An improved statistical approach for conformational analysis from 13C NMR chemical shifts

In this article we propose an improved statistical approach for the estimation of mole fraction each conformer in a given conformational equilibrium from measured averaged 13C NMR chemical shifts. As compound has different number conformers, iterative process fitting (backfitting type) is necessary. iteration, two estimates are made, i) to ridge regression model with equality and inequality constraints selection variables ii) re-fitting all compounds. This new procedure leads consistent results, low standard error good p-values, allowing composition small molecules reduced conformers.