Ethyl (E)-2-methoxy-imino-2-(4-nitro-benzo-yl)acetate.

The title mol-ecule, C(12)H(12)N(2)O(6), features an E conformation about the oxime group. The methoxy-imino and ester residues are effectively coplanar with each other (r.m.

(Z)-Ethyl 2-hydroxy-imino-2-(4-nitro-benz-yl)ethanoate.

The title mol-ecule, C(11)H(10)N(2)O(6), has a Z conformation about the C=N bond of the oxime unit. There are significant twists from planarity throughout the mol-ecule, the most significant being between the hydroxy-imino and ester groups which are effectively orthogonal with an N-C-C-O(carbon-yl) torsion angle of 91.4 (2)°.