Conformational Analysis of Open-Chain 1,2:3,4-Diepoxides: Comparison of Crystal Structures, NMR Data, and Molecular-Orbital Calculations

Article abstract of DOI:10.1002/hlca.19930760506

Several pairs of diastereomeric open-chain 1,2:3,4-diepoxides with different substitution patterns were prepared (see 3-9).As far as possible, crystal structures were determined to corroborate the relative configurations and to give insight into the solid-state conformations of these compounds.The comparison with our earlier molecular-orbital calculations and with 1H-NMR measurements shows that the solid-state conformations of eight out of the nine open-chain 1,2:3,4-diepoxides, whose crystal structures had been determined, correspond to substituted diepoxides of the erythro-series (e-6, e-7, e-9) seem to prefer the same conformation as in the crystal.The solution conformations of all other diepoxides differ from the arrangement in the solid state.