1,2-Vinylenebisphosphonium salts

The same kind of addition can be carried out on the ethynylphosphonium salt 26, generated in situ from the 1,2-vinylenebisphosphonium salt 25, and, depending on the experimental conditions, the vinylphosphonium salt produced can eventually undergo a second addition of YH to produce the / -acetalized or-thioacetalized salt. The same type of /Mieterosubstituted vinylphosphonium salt can also undergo an acidic hydrolysis that leads to the ketonic salt itself335 (reaction 74). 

TABLE 20. Alkaline hydrolysis of 1,2-ethylene- or 1,2-vinylenebisphosphonium salts... 

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