A Novel Access to 2-Aminofuranones via Cyclization of Functionalized γ-Hydroxy-α,β-butenoates Derived from N-Hydroxybenzotriazole Esters of α-Hydroxy Acids

The reaction between the N-hydroxybenzotriazole esters of substituted glycolic acids and alkyl cyanoacetates or malononitrile leads to the synthesis of y-hydroxy-functionalized butenoates which are cyclized under mild conditions to the corresponding 2-amino-3,5-disubstituted-4-furanones. That the products are optically active is confirmed by measurements of their optical rotations. On the other hand, replacement of N-hydroxybenzotriazole by N-hydroxysuccinimide might lead to by-products depending on the functionalized glycolic acid used.