The above observations do not allow a clear-cut interpretation of the mechanism of the reaction of 1 with nucleophiles. It is clear that anions of compounds with pK,> 19 (acetophenone, acetonitrile, dithiane) do not react successfully with 1, whereas anions derived from less basic substrates (pK,< 131, such as keto esters and malonates, give excellent yields of displacement products. However, it is not clear whether the ...