competes only mildly with hydroxylation at the tertiary C-H. The application of dioxirane 1b to polycyclic alkanes possessing a sufficiently rigid framework (such as 5 and 9) demonstrates the relevance of relative orientation of the cyclopropane moiety with respect to the proximal C-H undergoing oxidation. At one extreme, as observed in the oxidation of rigid spiro compound 9, even bridgehead tertiary
Dimethyldioxirane oxidations of some cyclopropanes
作者:Eckehard Volker Dehmlow、Noemi Heiligenstädt
DOI:10.1016/0040-4039(96)01107-0
日期:1996.7
Phenylcyclopropanes and halo-phenyl-substituted cyclopropanes do not react with dimethyldioxirane. Bicyclo[4.1.0]heptane (4), however, is oxidized by this reagent to the 2-ketone (5). Bicyclo[6.1.0]nonane (6) gives all three possile ketones (7 – 9). Even exo-9-bromobicyclo[6.1.0]nonane (10) can be converted by dimethyldioxirane to a ketone to which structure 11 is assigned.