title: New steroidal heterocycles: synthesis and structure of androst-2-eno[2,3-g](tetrazolo[1,5-a]pyridimines), androst-4-eno[3,2-f](tetrazolo-[1,5-a]pyrimidine), and androstano[17,16-f](tetrazolo[1,5-a]pyrimidines).
mesh_terms: D000731:Androstanes / Q000138:chemical synthesis; D000736:Androstenes / Q000138:chemical synthesis; D001378:Azasteroids / Q000138:chemical synthesis*; D055598:Chemical Phenomena; D002621:Chemistry; D011743:Pyrimidines / Q000138:chemical synthesis*; D013260:Steroids, Heterocyclic / Q000138:chemical synthesis*; D013777:Tetrazoles
chemical_list: D000731:Androstanes; D000736:Androstenes; D001378:Azasteroids; D011743:Pyrimidines; D013260:Steroids, Heterocyclic; D013777:Tetrazoles