Studies on the BF3·Et2O catalyzed Baeyer-Villiger reaction of spiroketalic steroidal ketones

Article abstract of DOI:10.1016/j.steroids.2010.12.004

During reactions of 23-oxosapogenins and the corresponding isomeric 22-oxo-23-spiroketals with MCPBA in the presence of BF₃· Et₂O, equilibration occurs between the ketones. The Baeyer-Villiger type oxidation is followed by fragmentation to the dinorcholanic lactones and 3-methylbutyrolactone. The mechanistic aspects of these reactions in the 25R and 25S series are discussed.