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Zur Regioselektivität SH‐haltiger Nucleophile gegenüber Androsta‐1,4‐dien‐3,17‐dion, einem Vorläufer für biologisch aktive Steroide
Author(s) -
Müller Anreas,
Weiß Dieter,
Beckert Rainer
Publication year - 1993
Publication title -
liebigs annalen der chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 0170-2041
DOI - 10.1002/jlac.199319930104
Subject(s) - chemistry , regioselectivity , thiol , nucleophile , catalysis , yield (engineering) , medicinal chemistry , biological activity , stereochemistry , selectivity , diene , organic chemistry , in vitro , biochemistry , materials science , metallurgy , natural rubber
On the Regioselectivity of SH‐Containing Nucleophiles towards Androsta‐1,4‐diene‐3,17‐dione, a Precursor for Biologically Active Steroids Thioketals have been prepared from androsta‐1,4‐diene‐3,17‐dione ( 1 ) and SH‐containing compounds in the presence of different catalysts. The thioketals 4 are obtained by using the aromatic thiols 3d , 3e , and 3g , whereas the aliphatic thiols 3a and 3c yield a mixture of regioisomeric products 4 – 6 . A higher selectivity with regard to the 17‐oxo group was observed by using the thiol 3b leading to 5b . With the araliphatic thiol 3f compound 5f is selectively formed. In contrast to the described thioketal formation, the thiol 3d yields in addition to 4d a double Michael addition product 7 , which was predominantly obtained by using other catalysts and/or a higher reaction temperature.