Progesterone 3-acetyl enol ether

Progesterone 3-acetyl enol ether, also known as progesterone acetate,^[1] as well as 3-acetoxypregna-3,5-dien-20-one, is a progestin which was never marketed.^[2][3][4][5] It was reported to possess similar potency to progesterone and hydroxyprogesterone caproate in the rabbit endometrial carbonic anhydrase test, a bioassay of progestogenic activity.^[2][3] In addition, it was able to maintain pregnancy in animals.^[2] Progesterone 3-acetyl enol ether is closely related to quingestrone, which is also known as progesterone 3-cyclopentyl enol ether and was formerly marketed as an oral contraceptive.^[6]

Progesterone 3-acetyl enol ether

Clinical data
Other names	Progesterone acetate; Progesterone 3-acetate; 3-Acetoxypregna-3,5-diene-20-one; 20-Oxopregna-3,5-dien-3-yl acetate; 3,5-Progesterol acetate; NSC-124740
Drug class	Progestogen; Progestogen ether
Identifiers
IUPAC name [(8S,9S,10R,13S,14S,17S)-17-Acetyl-10,13-dimethyl-2,7,8,9,11,12,14,15,16,17-decahydro-1H-cyclopenta[a]phenanthren-3-yl] acetate
CAS Number	4954-06-7 Y
PubChem CID	134580
ChemSpider	118613
UNII	7RB32A7QSD
Chemical and physical data
Formula	C23H32O3
Molar mass	356.506 g·mol−1
3D model (JSmol)	Interactive image
SMILES CC(=O)[C@H]1CC[C@@H]2[C@@]1(CC[C@H]3[C@H]2CC=C4[C@@]3(CCC(=C4)OC(=O)C)C)C
InChI InChI=1S/C23H32O3/c1-14(24)19-7-8-20-18-6-5-16-13-17(26-15(2)25)9-11-22(16,3)21(18)10-12-23(19,20)4/h5,13,18-21H,6-12H2,1-4H3/t18-,19+,20-,21-,22-,23+/m0/s1 Key:YIPYJRPRHUJJDP-WKOLOUIMSA-N

The 3-acetyl ether may be cleaved from progesterone 3-acetyl enol ether in vivo and, based on its chemical structure, this may result in the transformation of progesterone 3-acetyl enol ether into 3α-dihydroprogesterone and/or 3β-dihydroprogesterone. 3β-Dihydroprogesterone has been reported to possess about the same progestogenic potency as progesterone in the Clauberg test, whereas 3α-dihydroprogesterone was not assessed.^[7]

The C3 enol ethers of progesterone are less suited for use via depot injection relative to progestogen esters like hydroxyprogesterone caproate due to their susceptibility to oxidative metabolism.^[8]

See also

• Progestogen ester § Progestogen ethers
• List of progestogen esters § Ethers of progesterone derivatives