Abstract
Protonation of the highly reactive 1:l intermediate produced in the reaction
between triphenylphosphine and dimethyl acetylenedicarboxylate by 2-
hydroxyacetophenone leads to vinyltriphenylphosphonium salt, which undergoes
aromatic electrophilic substitution reaction with the conjugate base to produce
compounds 4,5, and 6 in 1 : 1.2:0.5 ratios
)