1247-70-7Relevant articles and documents
Production of 16β-(acetoxy)acetoxy derivatives by reaction of 17-keto steroid enol acetates with lead (IV) acetate
Numazawa, Mitsuteru,Shelangouski, Momoko,Nakakoshi, Masamichi
, p. 743 - 748 (2007/10/03)
Treatment of enol acetates of 3β-acetoxyandrost-5-en-17-one and its 5α-reduced analog, 5α-androstan-17-one, and estrone acetate, 1-4, with Pb(OCOCH3)4 in acetic acid and acetic anhydride gave the previously unreported products, 16β-(acetoxy)acetoxy-17-ketones 8-10 and 12, in 9-15% yields along with the known major products, 16β-acetoxy-17-ketones 5-7 and 11. Similar treatment of the 16β-acetoxy-17-ketones with the lead reagent did not yield the corresponding (acetoxy)acetates. Reaction of the enol acetate 3 with Pb(OCOCD3)4 in CD3COOD yielded principally the labeled (acetoxy)acetate 10-d3, which had a CD3COOCH2COO moiety at C-16β. In contrast, when the deuterated enol acetate 3-d3, which was obtained by treatment of the 17-ketone 14 with (CD3CO)2O in the presence of LDA and which had a CD3COO moiety at C-17, was reacted with Pb(OCOCH3)4, the resulting product was the labeled compound 10-d2. This product had a CH3COOCD2COO function at C-16β. Based on these results, along with further isotope-labeling experiments, it seems likely that the (acetoxy)acetate is produced through a lead (IV) acetate-catalyzed migration of the 17-acetyl function of the enol acetate to the C-16β-position followed by attack of an acetoxy anion of the lead reagent. Copyright
