566-75-6Relevant articles and documents
Site-selective oxidation, amination and epimerization reactions of complex polyols enabled by transfer hydrogenation
Hill, Christopher K.,Hartwig, John F.
, p. 1213 - 1221 (2017/11/28)
Polyoxygenated hydrocarbons that bear one or more hydroxyl groups comprise a large set of natural and synthetic compounds, often with potent biological activity. In synthetic chemistry, alcohols are important precursors to carbonyl groups, which then can be converted into a wide range of oxygen- or nitrogen-based functionality. Therefore, the selective conversion of a single hydroxyl group in natural products into a ketone would enable the selective introduction of unnatural functionality. However, the methods known to convert a simple alcohol, or even an alcohol in a molecule that contains multiple protected functional groups, are not suitable for selective reactions of complex polyol structures. We present a new ruthenium catalyst with a unique efficacy for the selective oxidation of a single hydroxyl group among many in unprotected polyol natural products. This oxidation enables the introduction of nitrogen-based functional groups into such structures that lack nitrogen atoms and enables a selective alcohol epimerization by stepwise or reversible oxidation and reduction.
Deoxygenation of steroidal ring-D 16,17-ketols with trimethylsilyl iodide
Nagaoka, Masao,Nagasawa, Etsuko,Numazawa, Mitsuteru
, p. 1857 - 1861 (2007/10/03)
Reaction of various steroidal 16,17-ketols, 16α-hydroxy-17-ketones 1- 3, and 15, 16β-hydroxy-17-ketone 4, and 17β-hydroxy-16-ketones 5-7, and 17, along with methyl ethers of 16α- and 17β-ketols 1 and 5, with an excess of trimethylsilyl iodide (TMSI) or with HI in CHCl3, produced the deoxygenated products, a mixture of the corresponding 17- and 16-ketones, in low to quantitative yields, in which the 17-ketone was the major product in each ease. When the 16β-deuterated 16α-ketol 3 and the 17α-deuterated 17β- ketol 7 were reacted with TMSI for a brief period (15 min), the deuterium content at C-16β and C-17α of the recovered steroids 3 and 7 was reduced by 17 and 35%, respectively. The present results indicate that the deoxygenation proceeds not only through a direct iodination pathway producing α-iodoketone but also through other reaction pathways.
PREPARATION OF 16-SUBSTITUTED 3-HYDROXYESTRA-1,3,5(10)-TRIENE-17-ONE STARTING WITH THE BROMINATION OF ESTRONE ACETATE
Fedorova, O. I.,Morozova, L. S.,Alekseeva, L. M.,Grinenko, G. S.
, p. 437 - 440 (2007/10/02)
The bromination of estrone acetate (Ia) leads to a mixture of acetates of 16α-bromo-16β-bromo-, and 16,16-dibromoestrone (IIa, IIIa, and IVa) in a ratio of 63:28:9.On treatment with an aqueous methanolic solution of potash, depending on the conditions, a mixture of (IIa) and (IIIa) gives 3,16α-dihydroxyestra-1,3,5(10)-trien-17-one (V) or 3,17β-dihydroxyestra-1,3,5(10)-trien-16-one (VI).When 5 g of (Ia) was brominated with 2.8 g of Br2 in chloroform and the products were chromatographed on silica gel, 0.36 g of (IVa), C20H22Br2O3, mp 165-166 deg C (from ether) 0.37 g of (IIIa), mp 169-170.5 deg C, 4.6 g of a mixture of (IIa) and (IIIa), 30 mg of (Ia) and 0.2 g of a mixture of 16α- and 16β-bromoestrones was obtained.The action of potash on a mixture of (IIa) and (IIIa) in aqueous MeOH at 20 deg C led to the epimerization of the (IIa) into (IIIa) and then the conversion of the latter into (V) with mp 203.5-206 deg C; diacetate with mp 172-173 deg C (acetone-ethanol).Similarly, but with heating (98 deg C, 3 h), a mixture of (IIa) and (IIIa) was converted into (VI), with mp 234-236 deg C.Characteristics of the IR and PMR spectra of the compounds obtained are given.
