Configurations and Conformations of Some Methyl-Substituted 2,4-DioxabicycloNonanes

Article abstract of DOI:10.1002/mrc.1260260618

Three dimethyl- and one trimethyl-2,4-dioxabicyclo<3.3.1>nonanes were prepared and their configurations and conformations were determined by means of multinuclear high-field NMR spectroscopy.Even at 400 MHz the proton spectra were so degenerated that several 2D experiments and, also, deuterium NMR had to be used to make the spectral analysis possible. 13C and 17O NMR spectra are also reported.The information obtained shows that two of the dimethyl derivatives are in boat-chair conformations with 3α9syn and 3α6α configurations, whereas the third dimethyl and the trimethyl derivative exist in chair-chair conformations with 3β9syn and 3β9syn9anti configurations. Methyl substituted 2,4-dioxa<3.3.1>nonanes Multinuclear NMR Configurational and conformational analysis Preparation.