Ruddock, Peter L.; Reese, Paul B.
Author Affiliation, Ana.
Department of Chemistry
The effect of 4b and 19 ester functionalities on some electrophilic addition reactions of D5-steroids
Date of Publication
The reactions of 3b-acyloxyandrost-5-enes with bromine/silver acetate (Petrow reaction) and mercury(II) trifluoroacetate (modified Treibs oxidation) have been used previously to effect allylic oxidation on these substrates en route to biologically active compounds. In both these reactions, which involve electrophilic addition to the D5-bond, the 3-acyloxy subtituent plays a significant role. In this report, the effect of introducing other substituents proximate to the D5-bond has been studied by using derivatives of 3b-acetoxyandrost-5-en-17-one (1), namely 3b,4b-diacetoxyandrost-5-en-17-one (13), 3b,19-diacetoxyandrost-5-en-17-one (14), 3b-acetoxyandrost-5-ene-7,17-dione (15), and 3b-acetoxy-4,4-dimethylandrost-5-en-17-one (17). Our results indicate that in both sets of reactions the effect of the introduced functional groups was pronounced. In the Petrow reaction, electrophilic addition rather than allylic oxidation on the diacetates was observed. With the Treibs reaction, allylic oxidation on the diactates occured. The 7-keto and 4,4-dimethyl steroids proved to be poor substrates in both reactions.....