(2R)-2-amino-4-methoxy-4-oxobutanoic acid (non-preferred name) D-aspartic acid, 4-methyl ester InChI=1/C5H9NO4/c1-10-4(7)2-3(6)5(8)9/h3H,2,6H2,1H3,(H,8,9)/t3-/m1/s