Abstract: Rates of eliminative ring fission of cyclic ethers bearing carbanion stabilizing groups have been measured with a view to assessing the contribution of ring strain to the ease of cleavage of bonds in elimination reactions.(Ethylsulfonylmethy1) oxiran (4) undergoes eliminative ring fission probably by the E2 mechanism. This occurs at least 2.5 million times as rapidly as elimination of methoxide ion from the acyclic model 14. In ...