β-Amino Ester Enolate as an Acrylate Anion Equivalent for the Synthesis of α-Methylene Esters, Acids, and Lactones

Article abstract of DOI:10.1021/jo00335a043

The lithium enolate (18) of methyl 3-(dimethylamino)propionate (17) has been developed as a synthetic equivalent of the α-anion (15) of acrylic acid.The enolate, obtained by treatment of the free ester (17) with lithium diisopropylamide, may be alkylated with a variety of alkyl halides to give products which may be considered to be protected acrylate esters.Unmasking is accomplished by quaternization with methyl iodide followed by DBN-induced elimination to give the free acrylates.The products derived from allylic halides may conveniently be converted into α-methylene lactones.