Answers are grounded in this paper and cite their sources.
Spectroscopic analysis demonstrates stereoelectronic control over hydrogen atom abstraction in ethers, indicating that orbital alignment governs radical reaction rates.
Relative rates of hydrogen atom abstraction by photogenerated tert-butoxyl from a variety of cyclic and acyclic ethers, acetals, and orthoformates have been measured at -60°C by an EPR spectroscopic technique. There is a pronounced stereoelectronic effect which produces high rates of abstraction from those C-H bonds adjacent to oxygen which have a relatively small dihedral angle (ca. 30°) with respect to the p-type orbital(s) on the oxygen(s). For C-H bonds which have a large dihedral angle (ca. 90°) abstraction is very much slower. The barrier to inversion of the 2-methoxy-1,3-dioxolan-2-yl radical is ≥10 kcal/mol.
No takes yet. Share an insight, caveat, or question.
Malatesta et al. (1981) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: