- Practical semisynthesis of equilenin and its derivatives
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Equilenin 2 and its derivatives are important intermediates in the synthesis of steroidal drugs. Until now, these estrogens were produced by extraction from pregnant mare's urine due to the lack of efficient synthetic methods. Most reported semisyntheses of equilenin involve expensive raw materials or toxic reagents to suppress undesired epimerization at C/D ring juncture. Herein, we reported a practical synthesis of highly pure equilenin and its derivatives from an easily available raw material 6 with conventional reagents.
- Yue, Tao,Li, Hong-Ping,Ding, Kai
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p. 4850 - 4853
(2016/10/07)
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- Acid catalysed reaction of indanones, tetralones and benzosuberone with neopentyl glycol and other alkanediols under forced conditions
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Upon reaction with an excess of 2,2-dimethylpropane-1,3-diol (neopentyl glycol, NPG) under acid catalysis, indanones and tetralones yield indenes and dihydronaphthalenes, respectively. The reaction can also be carried out with butane-1,3-diol.
- Imai, Masao,Morais, Goreti Ribeiro,Al-Hindawi, Bassam,Al-Sulaibi, Mazen A.M.,Meetani, Mohammad,Thiemann, Thies
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scheme or table
p. 325 - 329
(2010/10/19)
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- Acid catalysed reaction of estrones with neopentyl glycol under forced conditions
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Upon reaction with an excess of 2,2-dimethylpropane-1,3-diol (neopentyl glycol) under acid catalysis, estrones form 17-O-[2',2'-dimethyl-2'-(5", 5"-dimethyl-1",3"-dioxanyl)ethyl] substituted estra-3,17β-diols. The reaction represents a formal reduction of a keto function under acidic conditions in the absence of a metal.
- Oliveira, Cristina,Morais, Goreti Ribeiro,Imai, Masao,Inohae, Eiko,Yamamoto, Chishou,Mataka, Shuntaro,Thiemann, Thies
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experimental part
p. 158 - 162
(2010/08/06)
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- C(10)-C(19) bond cleavage reaction of 19-oxygenated androst-4-ene-3,6-dione steroids under various conditions
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C(10)-C(19) bond cleavage reaction of 19-hydroxy- and 19-oxoandrost-4-ene- 3,6,17-triones (5, 6) was explored under various conditions. Treatment of steroids 5 and 6 with KOH in MeOH gave the A-ring aromatized product 6-oxoestrone (11) in a fair yield, respectively, in contrast, the treatment with a weak base yielded 4-methyl steroid 17 (20%) in the case of 19-alcohol 5 or 19-nor- Δ5(10)-steroid 9 (12-67%) along with compound 11 (6-27%) in the case of 19-aldehyde 6. Reaction of compound 6 with HCl in MeOH produced 3-methyl ethers of 6-oxoestrone and Δ6-estrone, compounds 12 and 14 (ca. 20% each). Thus, 6-oxosteroids 5 and 6 showed unique C(10)-C(19) bond cleavage reactions with a base or acid.
- Nagaoka, Masao,Numazawa, Mitsuteru
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p. 983 - 985
(2007/10/03)
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- An Efficient Preparation of 6,7-Didehydroestrogenes
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The title compounds are prepared in excellent yield by palladium-catalyzed reduction with triethylammonium formate of enol triflates of 6-oxo-estrogens.
- Ciattini, Pier Giuseppe,Morera, Enrico,Ortar, Giorgio
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p. 1293 - 1297
(2007/10/02)
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