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Reaktionen von Steroid‐Hypojoditen VI. Substitutionen tertiärer Wasserstoffatome. Über Steroide, 200. Mitteilung
Author(s) -
Heusler K.,
Kalvoda J.
Publication year - 1963
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19630460619
Subject(s) - chemistry , allylic rearrangement , steric effects , medicinal chemistry , ether , double bond , hydrogen atom , substitution reaction , stereochemistry , organic chemistry , group (periodic table) , catalysis
The attack of an oxy radical (produced by the hypoiodite reaction) on a tertiary hydrogen atom, followed by base treatment, leads to an allylic ether: a 4α‐hydroxy‐5 βH‐steroid gives a Δ‐4α, 9α‐oxide as the main reaction product. It is postulated, that in cases where the initial 1,5‐hydrogen shift from carbon to oxygen leads to a sterically hindered carbon radical, the iodine atom does not combine with the radical. By transfer of an electron from carbon to iodine an ion pair is formed which decomposes by elimination of HI. The final allylic ether is produced by addition of a newly formed oxy radical to this double bond, followed by another oxidation and/or substitution elimination reaction.