A New and Convenient Method for the Synthesis of Dehydroamino Acids Starting from Ethyl N-Boc- and N-Z-α-Tosylglycinates and Various Nitro Compounds

Ethyl N-Boc- and N-Z-α-tosylglycinates, which were readily available from t-butyl or benzyl carbamate, ethyl glyoxylate, and sodium p-toluenesulfinate in formic acid, were reacted with a variety of nitro compounds in the presence of a base to afford the corresponding α,β-didehydroamino acid derivatives in good yields. Eventually, it was found that the (Z)-isomer was predominantly formed in the present method