ISSN:
0170-2041
Keywords:
Androsta-1,4-diene-3,17-dione
;
Thioketals
;
Hemithioketals
;
Steroids
;
Michael addition, double
;
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
On the Regioselectivity of SH-Containing Nucleophiles towards Androsta-1,4-diene-3,17-dione, a Precursor for Biologically Active SteroidsThioketals 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.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jlac.199319930104
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