Deuterium Isotope Effects in the Reaction of 4,4-Dimethyldihydropyran with Dimethyldioxirane

Article abstract of DOI:10.1021/jo00011a043

The reaction of dimethyldioxirane (1) with 4,4-dimethyl-2,3-dihydro-γ-pyran (2) gives the derived epoxide.Measured secondary deuterium isotope effects indicate that there is a greater degree of rehybridization at the β position (5-carbon) than at the α position (6-carbon) in the transition state leading to epoxide.The results are compared to those reported earlier in which 2 was oxidized by singlet oxygen to give the dioxetane.