Equilenin, also known as 6,8-didehydroestrone, as well as estra-1,3,5(10),6,8-pentaen-3-ol-17-one, is a naturally occurring steroidal estrogen obtained from the urine of pregnant mares.[1][2] It is used as one of the components in conjugated estrogens (brand name Premarin).[2] It was the first complex natural product to be fully synthesized, in work reported by 1940 by Bachmann and Wilds.[3]
Clinical data | |
---|---|
Other names | 6,8-Didehydroestrone; Estra-1,3,5(10),6,8-pentaen-3-ol-17-one |
Routes of administration | By mouth |
Drug class | Estrogen |
Identifiers | |
| |
CAS Number |
|
PubChem CID |
|
DrugBank |
|
ChemSpider |
|
UNII |
|
KEGG |
|
ChEBI |
|
ChEMBL |
|
CompTox Dashboard (EPA) |
|
ECHA InfoCard | 100.007.483 |
Chemical and physical data | |
Formula | C18H18O2 |
Molar mass | 266.340 g·mol−1 |
3D model (JSmol) |
|
| |
| |
(what is this?) (verify) |
The synthesis developed by the Bachmann group started from Butenand's ketone[4] – the 7-methoxy structural analog of 1,2,3,4-tetrahydrophenanthren-1-one[5] – and which can be readily prepared from 1,6-Cleve's acid.[6] The approach was based on well-established transformations like the Claisen condensation, the Reformatsky reaction, the Arndt–Eistert reaction, and the Dieckmann condensation.[3] Nicolaou described this preparation as ending the era preceding the post-World War II work of Robert Burns Woodward that introduced enantioselective synthesis;[4] in this synthesis, a mixture of stereoisomers were prepared and then resolved,[6] and the choice of target was partly because of the existence of only two chiral carbons and hence only four stereoisomers.[5]
The overall yield of the synthesis was 2.7% based on a twenty-step process starting from Cleve's acid.[6]