An approach for investigating the impacts of hydrogen bonding and stereochemical interactions of enol-enol tautomeric equilibria of β-dicarbonyl compounds is presented. DFT quantum chemical calculations of O–H⋯O ¹H NMR chemical shifts of enol pairs, weighted by their proportions^.as predicted by the relative free energies computed for them at the DFT level, agree well with experimental NMR chemical shifts. The main parameters affecting equilibrium constants for a set of eleven compounds, each one of which exists in two tautomeric forms in CHCl₃ solution, are ring strain and steric repulsion of substituents with differences in O–H⋯O hydrogen bond lengths playing a secondary role.

提出了研究β-二羰基化合物的烯键-烯醇互变异构平衡的氢键和立体化学相互作用的影响的方法。烯醇对的O–H⋯O ¹ H NMR化学位移的DFT量子化学计算，按其比例加权^。如通过在DFT水平上为其计算的相对自由能所预测的，与实验NMR化学位移非常吻合。影响一组11种化合物的平衡常数的主要参数，其中每种化合物在CHCl ₃溶液中以两种互变异构形式存在，其环应变和取代基的空间斥力（具有不同的O–H⋯O氢键长度）起着次要作用。