Triclinic modification of N-[(1,1-di­methyl­ethoxy)carbon­yl]-3-[(R)-prop-2-en-1-ylsulfin­yl]-(R)-alanine ethyl ester at 120 (1) K

There are two independent mol­ecules in the asymmetric unit of the title compound, C(13)H(23)NO(5)S. In the crystal structure, inter­molecular N—H⋯O hydrogen bonds link mol­ecules into two independent one-dimensional chains along [100]. The crystal studied was found to be a non-merohedral twin with a ratio of 0.615 (6):0.385 (1) for the refined components. At 200 (1) K [Singh et al. (2009 ▶). Acta Cryst. E65, o1385–o1386] the crystal structure of the title compound contains one disordered mol­ecule in the asymmetric unit of a monoclinic unit cell.