Ball-and-stick model of the (S)-enantiomer of the ketamine molecule, C₁₃H₁₆ClNO, as found in the crystal structure reported in B. Chankvetadze et al., J. Sep. Sci. 2002, 25, 1155-1166, DOI: 10.1002/1615-9314(20021101)25:15/17<1155::AID-JSSC1155>3.0.CO;2-M.

Note: The direction of optical rotation in (S)-ketamine depends on its conformation, which differs between salts and the free base. This image is from the crystal structure of the free base, (S)-(−)-ketamine, which has an equatorial phenyl group and exhibits optical rotation in the negative direction. In contrast, the hydrochloride salt of (S)-ketamine exhibits optical rotation in the positive direction and is thus known as (S)-(+)-ketamine hydrochloride. In the hydrochloride salt, the ketamine molecule has a different conformation, with an axial phenyl group. See File:S-(+)-ketamine-from-xtal-3D-balls.png for the three-dimensional structure.

Colour code:

  Carbon, C: black

  Hydrogen, H: white

  Chlorine, Cl: green

  Nitrogen, N: blue

  Oxygen, O: red