The solid-phase oxidation of steroidal alkenes with potassium permanganate and metal salts (original) (raw)
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ChemInform Abstract: Recent Developments in Oxidative Processes in Steroid Chemistry
ChemInform, 2012
Oxygenated steroids are bioactive compounds and valuable intermediates in the synthesis of biologically active products and APIs. This review will cover the literature from 2005/06 to the present concerning allylic oxidation, epoxidation and syn-dihydroxylation of alkenes, alcohol oxidation, and remote functionalization reactions of steroidal substrates.
Degradation of progestagens by oxidation with potassium permanganate in wastewater effluents
Chemistry Central Journal, 2013
Background: This study investigated the oxidation of selected progestagenic steroid hormones by potassium permanganate at pH 6.0 and 8.0 in ultrapure water and wastewater effluents, using bench-scale assays. Second order rate constants for the reaction of potassium permanganate with progestagens (levonorgestrel, medroxyprogesterone, norethindrone and progesterone) was determined as a function of pH, presence of natural organic matter and temperature. This work also illustrates the advantages of using a novel analytical method, the laser diode thermal desorption (LDTD-APCI) interface coupled to tandem mass spectrometry apparatus, allowing for the quick determination of oxidation rate constants and increasing sample throughput. Results: The second-order rate constants for progestagens with permanganate determined in bench-scale experiments ranged from 23 to 368 M -1 sec -1 in both wastewater and ultrapure waters with pH values of 6.0 and 8.0. Two pairs of progestagens exhibited similar reaction rate constants, i.e. progesterone and medroxyprogesterone (23 to 80 M -1 sec -1 in ultrapure water and 26 to 149 M -1 sec -1 in wastewaters, at pH 6.0 and 8.0) and levonorgestrel and norethindrone (179 to 224 M -1 sec -1 in ultrapure water and 180 to 368 M -1 sec -1 in wastewaters, at pH 6.0 and 8.0). The presence of dissolved natural organic matter and the pH conditions improved the oxidation rate constants for progestagens with potassium permanganate only at alkaline pH. Reaction rates measured in Milli-Q water could therefore be used to provide conservative estimates for the oxidation rates of the four selected progestagens in wastewaters when exposed to potassium permanganate. The progestagen removal efficiencies was lower for progesterone and medroxyprogesterone (48 to 87 %) than for levonorgestrel and norethindrone (78 to 97%) in Milli-Q and wastewaters at pH 6.0-8.2 using potassium permanganate dosages of 1 to 5 mg L -1 after contact times of 10 to 60 min. Conclusion: This work presents the first results on the permanganate-promoted oxidation of progestagens, as a function of pH, temperature as well as NOM. Progestagen concentrations used to determine rate constants were analyzed using an ultrafast laser diode thermal desorption interface coupled to tandem mass spectrometry for the analysis of water sample for progestagens.
ChemInform, 1992
There has been considerable interest in recent years in the synthesis of 5fi,6fi-epoxides of AS-unsaturated ster-oid~'-3 particularly since this functionality is present in a number of biologically active steroids such as withaferin A,4 withanolide B,S and jabarasalactone.6 Due to the (1) (a) Shiota, M.; Ogihara, T.; Watanabe, Y. Bull. Chem. SOC. Jpn. 1961,34,40. (b) Hmon, J. R.; Truneh, A. J. Chem. Soc., Perkin Tram. 1 1988,2001. (2) Muto, T.; Umehara, J.; Maeumori, H.; Miura, T.; Kimura, M.
Steroids, 2006
We have investigated the oxidative behavior of sterols such as cholesteryl acetate (1), 7-dehydrocholesteryl acetate (2), ergosteryl acetate (3), cholecalciferol acetate (Vitamin D3 acetate) (4) and ergocalciferol acetate (Vitamin D2 acetate) (5) with the oxidant system methyltrioxorhenium/H2O2/pyridine in order to check potential parameters controlling the selectivity. The reactions, performed in CH2Cl2/H2O at 25°C, have shown good regio- and stereoselectivity. All
Kerogen structural studies—oxidations with alkaline permanganate and with ferric chloride
Physics and Chemistry of the Earth, 1980
Two oxidizing agents were used for structural studies of the kerogen from Aleksinac shale (Yugoslavia), namely: (1) alkaline potassium permanganate, and (2) acidic ferric chloride. (1) The main goal with alkaline permanganate was to obtain optimum yields of identifiable oxidation products with preserved kerogen structural characteristics. In order to find optimal conditions, experiments were carried out at various temperatures (20-100°C) with varying amounts of permanganate per step. The best total yield of isolable degradation products (92.25%) was obtained at 75°C. At the same reaction temperature the best yield of ether-soluble acids was obtained (39% of the total organic matter). Kerogen degradation products obtained in high yields provide a better basis for more reliable structural interpretations than the products obtained in minor yields, which may represent small undefined portions of the original kerogen. (2) Ferric chloride is an oxidant of relatively high oxidation potential, although it is more gentle and more specific (e.g., dehydrogenation and decarboxylation) than most oxidation reagents containing oxygen used in kerogen structural studies. In oxidation of the Aleksinac shale kerogen concentrate with acidic ferric chloride solution, the pyrite content decreased (38-75%), and the kerogen content increased (7-15~). A small portion of the kerogen (-8~) was degraded into soluble products. The chemical nature of the kerogen was considerably changed. In addition to a decrease in the atomic H/C ratio and an increase in the O/C ratio, changes in the content of aliphatic, aromatic, carbonyl and quinoid structures were observed.