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Reinecke, Sebastian, Johnson, and Pyun pression, eq 6, may be written as v -(k2/Ki)h0 [CrVI][ RPNO], which agrees with the rate law reported for the oxidation of diphenylmethane in acetic acid.1 2345678 This indicates that the kinetic behavior is essentially the same in both the aqueous sulfuric and the acetic acid system. However, since the value of Ki presum-ably depends on the nature of the anions present,6 the equilibrium constants are not expected to be identical for the two solvent systems.

The vinyl anions derived from 2,3-dihydrofuran, 2,3-dihydro-4fi-pyran, and ethoxyethene have been examined by carbon-13 FT NMR. The vinyl C-H coupling constants (V13c_ih) have been measured for the ethers and the anions. Observation of vinyl anions derived from vinyl ethers is readily accomplished with carbon-13 NMR.While all carbon resonances are shifted upon formation of the anion the most obvious effect is the large (56-61 ppm) downfield shift of the vinyl carbon bonded to lithium. In no case was allylic deprotonation observed under the reaction conditions.