The molecular structure of cyclobutane has four carbon atoms, and its four carbon atoms are not in the same plane, which is the folded conformation of cyclobutane. Cyclobutane itself is not of commercial or biological interest, but more complex derivatives are important in biology and biotechnology. Currently, nine FDA-approved drugs contain the cyclobutane structure. From the perspective of therapeutic areas, cyclobutyl drugs are mainly distributed in popular areas such as tumors, neurological diseases, infectious diseases, endocrine and metabolic diseases.
Oxazolidines are five-membered ring compounds consisting of three carbons, nitrogen and oxygen. Oxygen and nitrogen are in the 1 and 3 positions, respectively. Oxazolidine is in general yellow or slightly yellow, alkaline liquid or solid, easily hydrolyzed by water or alcohol. It is insoluble in water (or hydrolyzed); soluble in benzene and chloroform. Oxazolidine derivatives are five-membered cyclic compounds containing at least one oxygen and nitrogen in their molecular structure. Oxazolidine derivatives are known to possess various therapeutic activities, such as anticancer and antibiotic properties.