3 [[(tert butyl)dimethylsilyl]oxy] 21 norpregn 17(20) ene 2 3 [[(tert butyl)dimethylsilyl]oxy] 21 norpregna 5,17(20) dien 16 ol 2 3 [[(tert butyl)dimethylsilyl]oxy] 5,17(20) dien 21 ol acetate 2 3 [[(tert butyl)dimethylsilyl]oxy]pregn 17(20) en 16 ol 2 3 [[(tert butyl)dimethylsilyl]oxy]pregn 17(20) en 16 ol acetate 2 3 [[(tert butyl)dimethylsilyl]oxy]pregn 17(20) ene 2 3 [[(tert butyl)dimethylsilyl]oxy]pregna 5,17(20) dien 16 ol 2 3 [[(tert butyl)dimethylsilyl]oxy]pregna 5,17(20) dien 21 ol 2 3 [[(tert butyl)dimethylsilyl]oxy]pregna 5,17(20) diene 2 Alkene moieties 2 Irradiation 2 Mass spectrometry 2 Nuclear magnetic resonance spectroscopy 2 Olefins 2 Oxygen 2 Oxygenated products 2 Photooxygenation 2 Reaction kinetics 2 Steroids 2 alkene 2 androstane derivative 2 article 2 carbon nuclear magnetic resonance 2 chemical reaction 2 epiandrosterone 2 ethylene oxide 2 hydroperoxide 2 irradiation 2 mass spectrometry 2 matrix assisted laser desorption ionization time of flight mass spectrometry 2