10.1039/jr9390001356
The study investigates the reactions of α- and β-cholesteryl benzoate oxides, which are prepared through the treatment of cholesteryl benzoate with perbenzoic acid. These oxides are key compounds in the research. α-Cholesteryl benzoate oxide, when treated with hydrochloric acid, yields 6-chloro-5-hydroxy-3-benzoyloxycholestane, which upon dehydration forms 6-chloro-3-benzoyloxy-A4-cholestene. Similarly, β-cholesteryl benzoate oxide reacts with hydrochloric acid to produce 5-chloro-6-hydroxy-3-benzoyloxycholestane. The study also explores the isomerization of α-cholesteryl benzoate oxide to 6-ketocholestanyl benzoate using dehydrated alum or phosphoric oxide. Additionally, the researchers attempted to replicate the preparation of α-benzoate oxide via pyrolysis of the dibenzoate of 3:5:6-trihydroxycholestane, but encountered issues with impurities. The study provides detailed experimental procedures and characterizations of the compounds involved, highlighting the differences in behavior between α- and β-cholesteryl benzoate oxides and their derivatives.
10.1016/S0040-4020(01)97207-2
The research investigates the use of 2-pyridineseleninic anhydride as an efficient reagent for converting olefins to unsaturated ketones while retaining the original position of the double bond. This reagent is more reactive towards olefins than benzeneseleninic anhydride. The study was inspired by the observation that the model alkyl-2’-pyridylselenide underwent allylic oxidation by 2-pyridineseleninic anhydride generated in situ from the oxidation of dipyridyldiselenide with iodoxybenzene. The researchers tested this hypothesis using various model olefins and found that 2-pyridineseleninic anhydride, conveniently introduced as 2,2’-dipyridyldiselenide, effectively catalyzed the allylic oxidation of olefins to ketones. The study also explored the use of m-iodoxybenzoic acid and iodosobenzene as oxidants and demonstrated the system's effectiveness on various substrates, including cholesteryl benzoate and geraniol acetate. The research highlights the potential of this new allylic oxidation system based on an organoselenium catalyst for clean and selective oxidation of olefins without the need for aqueous work-up.
