
TY  - JOUR
A1  - Pinhey, JT 
A1  - Schaffner, K 
T1  - 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
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1968
VL  - 21
IS  - 7
SP  - 1873
EP  - 1889
KW  - 
UR  - https://doi.org/10.1071/CH9681873 
N2  - 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. 
ER  -

