CAS No 595-77-7 , (8R,9S,10R,13S,14S,16R,17S)-17-acetyl-16,17-dihydroxy-10,13-dimethyl-2,
6,7,8,9,11,12,14,15,16-decahydro-1H-cyclopenta[a]phenanthren-3-one

Title: Algestone
CAS Registry Number: 595-77-7
CAS Name: (16a)-16,17-Dihydroxypregn-4-ene-3,20-dione
Synonyms: 16a,17-dihydroxyprogesterone; 4-pregnene-16a,17a-diol-3,20-dione; alphasone
Molecular Formula: C21H30O4
Molecular Weight: 346.46
Percent Composition: C 72.80%, H 8.73%, O 18.47%
Literature References: Prepn from 16-dehydroprogesterone: Inhoffen et al., Ber. 87, 593 (1954); Cooley et al., J. Chem. Soc. 1955, 4373; Allen, Bernstein, J. Am. Chem. Soc. 78, 1909 (1956); Hydorn et al., Steroids 3, 493 (1964). Manuf from 16-dehydroprogesterone: Colton, US 2727909 (1955 to Searle); Hydorn et al., US 3165541 (1965 to Olin Mathieson); from its 16a-acetate: Diassi, US 3027384 (1962 to Olin Mathieson).
Properties: Needles from ethanol + dichloromethane, mp 225°. [a]D22 +95° (c = 0.81 in CHCl3). uv max: 240 nm (e 16600).
Melting point: mp 225°
Optical Rotation: [a]D22 +95° (c = 0.81 in CHCl3)
Absorption maximum: uv max: 240 nm (e 16600)
 
Derivative Type: Cyclic acetal with acetone
CAS Registry Number: 4968-09-6
Synonyms: 16a,17-[(1-Methylethylidene)bis(oxy)]pregn-4-ene-3,20-dione; algestone acetonide; alphasone acetonide; 16a,17a-isopropylidenedioxyprogesterone
Molecular Formula: C24H34O4
Molecular Weight: 386.52
Percent Composition: C 74.58%, H 8.87%, O 16.56%
Literature References: Prepn: Cooley et al., loc. cit; Fried et al., Chem. Ind. (London) 1961, 465.
Properties: Needles from aq ethanol, mp 210°. [a]D20 +137° (c = 0.7 in CHCl3).
Melting point: mp 210°
Optical Rotation: [a]D20 +137° (c = 0.7 in CHCl3)
 
Derivative Type: 16a-Methyl ether
Synonyms: 17-Hydroxy-16a-methoxypregn-4-ene-3,20-dione
Molecular Formula: C22H32O4
Molecular Weight: 360.49
Percent Composition: C 73.30%, H 8.95%, O 17.75%
Literature References: Prepd from the free diol via 16a,17-dihydroxypregn-4-ene-3,20-dione cyclic borate: Fried, US 3006930 (1961 to Olin Mathieson).
Properties: Crystals from 95% ethanol, mp 142-143°. [a]D23 +60° (c = 0.15 in CHCl3). uv max: 234 nm (e 15400).
Melting point: mp 142-143°
Optical Rotation: [a]D23 +60° (c = 0.15 in CHCl3)
Absorption maximum: uv max: 234 nm (e 15400)
 
Therap-Cat: Acetonide as anti-inflammatory (topical).
Keywords: Glucocorticoid.