Configurational assignments of diastereomeric γ-lactones using vicinal H–H NMR coupling constants and molecular modelling†
Abstract
The conformational features of four diastereomers of the γ-lactone 2-ethyl-4-methyl-5-oxotetrahydrofuran-3-carboxylic acid were investigated by calculations which included molecular mechanics (MM3), semiempirical (AM1) and ab initio molecular orbital theory (HF/6-31G), the latter including