Answers are grounded in this paper and cite their sources.
The Ramirez ylide undergoes electrophilic substitution with acetylenedicarboxylates to form Z and E adducts. The latter can react by cycloaddition with another equivalent of the alkyne to provide a new route to novel tetra-substituted azulenes, which show interesting bond localisation and crystal packing effects.
No takes yet. Share an insight, caveat, or question.
Higham et al. (2004) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: