Analogifremgangsmaade for the preparation of therapeutically active heparin fragments

Heparin fragments having selective anticoagulation activity having 14-18 sugar units, the disaccharide unit L-iduronosyl-2-O-sulphate-N-sulpho-U-glucosamine-6-O-sulphate being the main component, and where unsulphated L-iduronic acid is in a position situated 3-5 sugar units from the unreducing terminal. Pharmaceutical compositions containing such heparin fragments. Processes for the preparation of the heparin fragments.