Combining the Power of J Coupling and DP4 Analysis on Stereochemical Assignments: The J-DP4 Methods

A systematic study to include ³ JHH couplings into DP4 formalism ( J-DP4) led to the development of three alternative strategies. The d J-DP4 (direct) approach involves a new DP4-like equation including an additional probability term given by ³ JHH. The i J-DP4 (indirect) approach explores the original DP4 method with a restricted conformational search. Despite both strategies performing better than DP4, their combined use (i J/d J-DP4) provided the best results, with a 2.5-fold performance improvement at similar or lower computational cost.