| Title:  Equilenin CAS Registry Number:  517-09-9 CAS Name:  3-Hydroxyestra-1,3,5,7,9-pentaen-17-one Additional Names:  11,12,13,14,15,16-hexahydro-3-hydroxy-13-methyl-17H-cyclopenta[a]phenanthren-17-one;  1,3,5:10,6,8-estrapentaen-3-ol-17-one Molecular Formula:  C18H18O2 Molecular Weight:  266.33 Percent Composition:  C 81.17%, H 6.81%, O 12.01% Literature References:  Estrogenic steroidal hormone isolated from urine of pregnant mares:  Girard et al., Compt. Rend. 195, 981 (1932).  Occurs naturally in the d-form.  Not found in human urine.  Component of Conjugated Estrogenic Hormones, q.v.  Isoln by chromatography:  Duschinsky, Lederer, Bull. Soc. Chim. Biol. 17, 1534 (1935).  Total synthesis:  Bachmann et al., J. Am. Chem. Soc. 61, 974 (1939); 62, 824 (1940); Johnson et al., ibid. 67, 2274 (1945); 69, 2942 (1947); 72, 505 (1950); Hughes, Smith, Chem. Ind. (London) 1960, 1022; Bailey et al., Chem. Commun. 1967, 1253; Stein et al., Tetrahedron 26, 1917 (1970).  Synthesis from estrone:  Corbellini et al., Farmaco Ed. Sci. 19, 913 (1964); O. N. Minailova et al., Zh. Obshch. Khim. 49, 2633 (1979); A. R. Daniewski, T. Kowalczyk-Przewloka, Tetrahedron Lett. 1982, 2411.  Review of synthetic studies:  Taub, "Naturally Occurring Aromatic Steroids" in The Total Synthesis of Natural Products vol. 2, J. ApSimon, Ed. (John Wiley & Sons, New York, 1973) pp 642-663. Properties:  Needles from dil alc, mp 258-259°.  Sublimes at 170-180° at 0.01 mm Hg.  [a]D16 +87° (12.8 mg made up to 1.8 ml in dioxane).  uv max (ethanol):  231, 270, 282, 292, 325, 340 nm.  Soly/100 ml alcohol 0.63 (18°); 2.5 g (boiling). Melting point:  mp 258-259° Optical Rotation:  [a]D16 +87° (12.8 mg made up to 1.8 ml in dioxane) Absorption maximum:  uv max (ethanol):  231, 270, 282, 292, 325, 340 nm   Derivative Type:  Acetate  Molecular Formula:  C20H20O3 Molecular Weight:  308.37 Percent Composition:  C 77.90%, H 6.54%, O 15.57% Properties:  mp 156-157°. Melting point:  mp 156-157°   Derivative Type:  Benzoate  Molecular Formula:  C25H22O3 Molecular Weight:  370.44 Percent Composition:  C 81.06%, H 5.99%, O 12.96% Properties:  mp 222-223° (vac). Melting point:  mp 222-223° (vac)   Derivative Type:  Methyl ether  Molecular Formula:  C19H20O2 Molecular Weight:  280.36 Percent Composition:  C 81.40%, H 7.19%, O 11.41% Properties:  Needles from alc, mp 197-198°; mp 193-194° (vac). Melting point:  mp 197-198°; mp 193-194° (vac)   Therap-Cat:  Estrogen. Keywords:  Estrogen; Steroidal.  |