Synthesis of α-Vinyl Amino Acids.

This chapter presents procedures for the synthesis of α-vinyl amino acids, in which the usual α-proton is replaced by an unsubstituted vinyl group (Fig. 1). The parent member of this family, α-vinylglycine (R≠H), is a natural product (1,2) and acts as a suicide substrate for a number of PLP-dependent enzymes (4-9). Higher members of this family (R≠H) have also been synthesized (10-12). Several including α-vinyl-m-tyrosine (13-15), α-vinyl-DOPA (13-15), α-vinylglutamate (16), α-vinylornithine (17), α-vinyllysine (18), and α-vinylarginine (18) are Trojan horse inhibitors of their cognate amino acid decarboxylases (AADCs). Such (appropriately labeled) AADC inhibitors may also have potential as reagents for positron emission tomography (19). Fig. 1. Generic structure for α-vinyl amino acids.