In the course of recent studies on additions of allenylzinc reagents, prepared from propargylic mesylates as described above, to conjugated aldehydes, we encountered an unforeseen side reaction in which an ethyl group from the diethylzinc was transferred to the β-position of (E)-2-heptenal in a 1,4-addition reaction (Figure 2). 2 In a separate experiment, we found that the 1,4-ethyl adduct was produced in high yield from the enal and diethylzinc in the ...
