levonorgestrel cyclobutylcarboxylate levonorgestrel cyclobutylcarboxylate levonorgestrel cyclobutylcarboxylate (or levonorgestrel 17β-cyclobutylcarboxylate; developmental code name hrp-001) is a progestin and a progestogen ester which was studied for potential use as an injectable hormonal contraceptive but was never marketed. it was developed by the world health organization's special programme on human reproduction in the 1980s. analogues of levonorgestrel cyclobutylcarboxylate include levonorgestrel butanoate (hrp-002) and levonorgestrel cyclopropylcarboxylate (hrp-003). levonorgestrel cyclobutylcarboxylateclinical dataother nameshrp-001; hrp001; levonorgestrel cyclobutyl-carboxylate; levonorgestrel cyclobutanecarboxylate; levonorgestrel 17β-cyclobutylcarboxylate; 17α-ethynyl-18-methyl-19-nortestosterone 17β-cyclobutylcarboxylate; 17α-ethynyl-18-methylestr-4-en-17β-ol-3-one 17β-cyclobutylcarboxylate; 13-ethyl-17α-hydroxy-18,19-dinorpregn-4-en-20-yn-3-one cyclobutanecarboxylateroutes ofadministrationintramuscular injectiondrug classprogestogen; progestin; progestogen esteridentifiers iupac name phenanthren-17-yl] cyclobutanecarboxylate cas number86679-36-9pubchem cid10092040chemspider21165289comptox dashboard (epa)dtxsid00235759 echa infocard100.081.126 chemical and physical dataformulac26h34o3molar mass394.555 g·mol−13d model (jsmol)interactive image smiles cc12cc3(1cc2(c#c)oc(=o)c4ccc4)ccc5=cc(=o)cc35 inchi inchi=1s/c26h34o3/c1-3-25-14-12-21-20-11-9-19(27)16-18(20)8-10-22(21)23(25)13-15-26(25,4-2)29-24(28)17-6-5-7-17/h2,16-17,20-23h,3,5-15h2,1h3/t20-,21+,22+,23-,25-,26-/m0/s1key:wwgtwfpuipehnx-uknjcjgysa-n