Improved synthesis of a protected 11-oxoestrone.
An improved synthesis of 11-oxoestrone-3-acetate-17-ethyleneketal is reported. Adjustments are proposed for the oxidation of estrone by 2,3-dichloro-5,6-dicyano-1,4-benzoquinone into 9(11)-dehydroestrone. A complete hydroboration-oxidation of the resulting ketal, by means of borane-methylsulfide complex, gives the corresponding 11-hydroxy derivative. This latter compound is then acetylated for successful oxidation with pyridinium chlorochromate on alumina. The overall yield is 30%.
Stéphan
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Laboratoire de Chimie Organométallique, associé au CNRS, ENSCP, Paris, France.
Zen
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Authier
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Jaouen
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D000107:Acetylation; D000537:Aluminum Oxide / Q000737:chemistry; D002840:Chromates / Q000737:chemistry; D004970:Estrone / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D010084:Oxidation-Reduction; D011726:Pyridinium Compounds / Q000737:chemistry; D013141:Spiro Compounds / Q000138:chemical synthesis*
C099732:11-oxoestrone-3-acetate-17-ethyleneketal; D002840:Chromates; D011726:Pyridinium Compounds; D013141:Spiro Compounds; C099731:chlorotrioxochromic acid; D004970:Estrone; D000537:Aluminum Oxide