0,7-Acetylenecarboxylic acid acetylene derivs

Acetylenic esters react well with copper-zinc compounds. Propiolic esters are especially reactive [83], but other acetylenecarboxylic acid derivatives such as dimethyl acetylenedicarboxylate or propiolamide 118 undergo highly stereoselective cis addition (Scheme 2.47) [46]. 

Acetylenecarboxylic esters, reactions with nitrogen-containing heterocycles, 23, 263 Acetylenic derivatives of pyrazoles, synthesis and properties of, 82, 1 Acetylenic esters, synthesis of heterocycles through nucleophilic additions to, 19,297 Acid-catalyzed polymerization of pyrroles and indoles, 2, 287... 

Ethylmagnesium bromide Acetylenecarboxylic acids from acetylene derivatives... 

The transformation of a-pyrones to benzene and carbon dioxide upon their cycloaddition with acetylene, and the reaction of 2//-pyrans to yield benzoic acid derivatives when exposed to acetylenecarboxylates are conceptually related processes (see Scheme 2.3). These are, strictly speaking, retro Diels-Alder reactions," some of which embody interesting mechanistic problems. 

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