(J anuary 8, 1965) 7-Acetamido·7-deoxY-L-galacto-hep tulose was prepared by oxidation of l-acetamido-l-deoxy-oglycero-o-galacto-heptitol with Acetobacter suboxydans. The new acetamido-deoxY-L-heptu lose was shown to be a pyranose by compari son with ,B-o-fructopyranose. The following eq uat ions re prese nt the optical rotation of 7-acetamido-7-deoxy-a-L-galacto-heptulopyranose in water at 20°C and 3 .5 °C, respec tive ly :[aJ'°o =-15.5e-·o3961 -97.1, [aJ'-' o =-1l.ge-· o1oll -105.8, whe re t is the tim e in minutes after dissolution of th e s ampl e.