The behaviour of organopotassium intermediates derived from oxiranes under the influence of alkalide K−, K+(15-crown-5)2

Organopotassium intermediates derived from monosubstituted oxiranes by alkalide K−, K+(15-crown-5)2 are generally unstable at ambient temperature. They undergo further fast reactions. There are three groups of these organometallic compounds. The first one reacts exclusively with 15-crown-5. The second reacts only with the oxirane substrate. The third reacts both with crown ether and with the appropriate oxirane, and one of these undergoes γ-elimination. The most interesting seems to be the first type of the reaction. It leads to the crown ring cleavage. Potassium tetraethylene glycoxide vinyl ether is the product of the reaction. Crown ether plays a dual role in this case. It takes part in the process both as a complexing agent and as a reagent.