N-acetyl-L-tyrosine methyl ester monohydrate at 293 and 123 K.

The crystal structure of a protected L-tyrosine, namely N-acetyl-L-tyrosine methyl ester monohydrate, C(12)H(15)NO(4).H(2)O, was determined at both 293 (2) and 123 (2) K. The structure exhibits a network of O-H...O and N-H...O hydrogen bonds, in which the water molecule plays a crucial role as an acceptor of one and a donor of two hydrogen bonds. Molecules of water and of the protected L-tyrosine form hydrogen-bonded layers perpendicular to [001]. C-H...pi interactions are observed in the hydrophobic regions of the structure. The structure is similar to that of N-acetyl-L-tyrosine ethyl ester monohydrate [Soriano-García (1993). Acta Cryst. C49, 96-97].