ERROR opening https://cactus.nci.nih.gov/chemical/structure/O%3DC%5C1c3c%28O/C%3DC/1%29cc2occc2c3/file?format=sdf&get3d=True  -- O%3DC%5C1c3c%28O/C%3DC/1%29cc2occc2c3 could not be loaded.