text: Several modifications of alkynylation reactions are known:
  * In the Arens–van Dorp synthesis the compound ethoxyacetylene is converted to a Grignard reagent and reacted with a ketone, the reaction product is a propargyl alcohol.
  * The Isler modification is a modification of Arens–Van Dorp Synthesis where ethoxyacetylene is replaced by β-chlorovinyl ethyl ether and lithium amide.