Merck, 220868-10G, 1-Acetoxy-1,3-butadiene

General description
1-Acetoxy-1,3-butadiene (1-ABD) can be generated by potassium or sodium acetate catalyzed reaction between crotonaldehyde and acetic anhydride. The product is a mixture of cis and trans forms, that has been confirmed by its physical properties and IR spectra. It is reported to be formed as a major product during the acetoxylation of 1,3-butadiene (BD) in gas-phase in the presence of Pd-KOAc (palladium-potassium acetate) catalyst. 1-ABD participates as 2Π or 4Π diene in cycloaddition reactions. Enantioselective Diels Alder reaction of 2-methoxy-5-methyl-1,4-benzoquinone with 1-ABD in the presence of molecular sieves (mesh size:4Å) has been reported.
Application
1-Acetoxy-1,3-butadiene was used as diene in the following reactions:
Diels-Alder reaction with ortho-carbazolequinones to yield benzocarbazolequinone.
Diels-Alder reaction with diethyl ketovinylphosphonate, with and without Lewis acid assistance.
Diels-Alder reaction with methyl acrylate to yield racemic forms of 2-hydroxy-3-cyclohexenecarboxylic acid.

It was used for the reaction with dienophiles such as maleimides, a juglone, a butyne-1,4-dione and methyl 2-(4-methylphenyl)-2H-azirine-3-carboxylate and during visible light photocatalysis. It was also used as reactant during intermolecular oxa-Pictet-Spengler cyclization.