Download PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... A general synthesis of new alkyl 4-alkyl-2-hydroxy-3-oxo-3,4-dihydro-2H-1,4-benzoxazine-2-carboxylate peptidomimetic building blocks from the corresponding alkyl 3-oxo-3,4-dihydro-2H-1,4-benzoxazine -2-carboxylates through carbanion oxidation is described.