Synthesis of -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.