Hydrogen bonding and steric effects on rotamerization in 3,4-alkylenedioxy-, 3-alkoxy- and 3,4-dialkoxy-2-thienyldi(tert-butyl)methanols: an NMR, IR and X-ray crystallographic studyElectronic supplementary information (ESI) available: NMR data; activation parameters for rotation; MMFF94 steric energies and alkoxy group geometries; thermodynamic data; quantum mechanical calculations of geometries; bond lengths, bond angles and torsion angles of 8A-Et; NMR and IR data on new compounds. See http://www.rsc.org/suppdata/p2/b1/b109612p/
作者:John S. Lomas、Alain Adenier、Kun Gao、François Maurel、Jacqueline Vaissermann
DOI:10.1039/b109612p
日期:2002.1.23
largely determined by steric effects but intramolecular hydrogen bonding in the anti isomer contributes to the variation of the anti → syn rotation barrier. A single crystal X-ray diffraction study of the anti-3,4-diethoxy derivative shows that the orientation of the 3-alkoxy group is very different from that in anti-3-methoxy-2-thienyldi(1-adamantyl)methanol. Molecularmechanics and quantum mechanical calculations