The use of ethoxyacetylene in organic synthesis is well-known." b The condensation of ketones or aldehydes with the anion of ethoxyacetylene yields carbinols, which may be converted to a,@-unsaturated esters, aldehydes, or carboxylic Ethoxyacetylene undergoes cycloaddition reactions with ketenes to form cyclobutenone ethem2g-'It has also been used as a coupling reagent in the synthesis of peptides2j and acid anhydrides. 2b Although ...