Convenient general preparation of oxygenated monofluoro- and gem-difluoro-5a-androstanes using diethylaminosulphur trifluoride
作者:T. Geoffrey C. Bird、Peter M. Fredericks、Ewart R. H. Jones、G. Denis Meakins
DOI:10.1039/c39790000065
日期:——
Hydroxy-ketones in the 5α-androstane series are converted into fluoro-ketones by diethylaminosulphurtrifluoride under mild conditions; acetoxy-ketones give acetoxydifluorides under more vigorous conditions.
Efficient cleavage of cyclopropyl bond by adjacent ketyl radical generated under PET conditions
作者:Bipin Pandey、Ashok T. Rao、Pramod V. Dalvi、Pradeep Kumar
DOI:10.1016/s0040-4020(01)90404-1
日期:1994.3
Photolysis of various conjugated cyclopropyl and epoxy ketones in 20% triethyl amine (TEA) and ethanol leads to cleavage of cyclopropyl bond. Significant wavelength dependence phenomenon is observed during photolysis for the cleanliness and efficient photo transformation. Steroidal cyclopropyl ketones cleave efficiently at 300nm photolysis, whereas exo-cyclopropyl ketones cleave at 254nm. The regiochemistry
Conformational free energy differences in steroids. Part V. Equilibration of 5α- and 5β-androstan-6-one derivatives structurally modified in ring<scp>D</scp>
作者:D. Neville Jones、R. Grayshan
DOI:10.1039/j39700002421
日期:——
The presence of 17β-groups (methoxy-, acetoxy-, ethyl, or 1,5-dimethylhexyl) or of unsaturation in ringD had little effect upon the position of equilibrium between substituted 5α- and 5β-androstan-6-ones.