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.^{[1][2][3][4][5][6][7][8][9][10]} It was developed by the World Health Organization's Special Programme on Human Reproduction in the 1980s.^[1][2][9] Analogues of levonorgestrel cyclobutylcarboxylate include levonorgestrel butanoate (HRP-002) and levonorgestrel cyclopropylcarboxylate (HRP-003).^[1][2][3]

Levonorgestrel cyclobutylcarboxylate

Clinical data
Other names	HRP-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 cyclobutanecarboxylate
Routes of administration	Intramuscular injection
Drug class	Progestogen; Progestin; Progestogen ester
Identifiers
IUPAC name [(8R,9S,10R,13S,14S,17R)-13-Ethyl-17-ethynyl-3-oxo-1,2,6,7,8,9,10,11,12,14,15,16-dodecahydrocyclopenta[a]phenanthren-17-yl] cyclobutanecarboxylate
CAS Number	86679-36-9
PubChem CID	10092040
ChemSpider	21165289
CompTox Dashboard (EPA)	DTXSID00235759
ECHA InfoCard	100.081.126
Chemical and physical data
Formula	C26H34O3
Molar mass	394.555 g·mol−1
3D model (JSmol)	Interactive image
SMILES CC[C@]12CC[C@H]3[C@H]([C@@H]1CC[C@]2(C#C)OC(=O)C4CCC4)CCC5=CC(=O)CC[C@H]35
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/s1 Key:WWGTWFPUIPEHNX-UKNJCJGYSA-N

See also

• List of progestogen esters § Esters of 19-nortestosterone derivatives
• Progestogen-only injectable contraceptive