
%0 Journal Article
%A Pinhey, JT 
%A Schaffner, K 
%T Baeyer-Villiger oxidation of &#916;<sup>4</sup>-3-Oxo-steroids and 4,5-Epoxy-3-oxo-steroids. A route to some novel A-nor-steroids
%J Australian Journal of Chemistry
%D 1968/07/01
%V 21
%N 7
%P 1873-1889
%K 
%R https://doi.org/10.1071/CH9681873
%U https://www.publish.csiro.au/paper/CH9681873 
%X Evidence is presented that the Baeyer-Villiger oxidation of &#916;4-3-oxo-steroids yields enol-e-lactones which are further oxidized to &#946;-epoxy-e-lactones. The latter are acid labile and rearrange to 5&#945;-acyl-&#8706;-lactones. The sequence appears to be stereospecific, and no 5&#946;-acyl-&#8706;-lactones could be isolated.   Baeyer-Villiger oxidation of 4,5-epoxyoholestan-3-ones results in oxygen insertion between C3 and C4. The epoxy-e-lactones were not isolated, since they rearranged under the acidic conditions to give 5-acyl-4-oxacholestan-3-ones. The 5&#945;-acyl epimers differ from the 5&#946;-compounds, by undergoing an internal Claisen-type condensation to give A-norcholestans with a 2,5-lactone bridge. The photochemical, thermal, and boron trifluoride-catalysed conversion of the enol lactone (IIIa) into a-nor-5&#946;-cholestan-3-one is reported. 
