ERROR opening https://cactus.nci.nih.gov/chemical/structure/COC1%3DC%28C%28%3DC2CNCCC2%3DC1%29O%29OC/file?format=sdf&get3d=True  -- COC1%3DC%28C%28%3DC2CNCCC2%3DC1%29O%29OC could not be loaded.