Stereoelectronic Effects in Hydrogen Atom Abstraction from Substituted 1,3-Dioxanes

Article abstract of DOI:10.1021/ja00393a019

An EPR technique and a method involving the gas chromatographic determination of the relative rates of consumption of substrates have been employed to measure the relative rates of hydrogen atom abstraction by tert-butoxy radicals from various substituted 1,3-dioxanes.The high relative reactivities of dioxanes equitorially substituted at C-2 as compared with their axially substituted epimers are attributed to the favorable stereoelectronic interactions in the former between the axial C-H bonds and adjacent oxygen lone pairs.The effects of methoxy substituents on the relative reactivities of cyclic ethers have been similarly rationalized.The photoinduced reaction between benzophenone and the methoxydioxane (8) has been shown to be reversible.