- A convenient synthesis of the side chain of loteprednol etabonate - An ocular soft corticosteroid from 20-oxopregnanes using metal-mediated halogenation as a key reaction
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A facile synthesis of the side chain of loteprednol etabonate, namely, chloromethyl-17α-[(ethoxycarbonyl))oxy]-11β-hydro of loteprednol etabonate, viz., chloromethyl-17α-[(ethoxycarbonyl))oxy]-11xy-3- oxoandrosta-1,4-diene-17β-carboxylate - an ocular soft corticosteroid, has been described starting from a 20-oxopregnane, namely, 3β-acetoxy-pregn- 5(6),16(17)-diene-20-one (16-dehydropregnenolone acetate, i.e., 16-DPA) using our recently developed metal-mediated halogenation as a key reaction.
- Chowdhury, Pritish,Borah, Juri Moni,Goswami, Papori,Das, Archana Moni
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experimental part
p. 497 - 501
(2011/05/09)
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- Potential corticoid metabolites: Chemical synthesis of 3- and 21-monosulfates and their double-conjugates of tetrahydrocorticosteroids in the 5 α- and 5 β-series
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Here, we describe the chemical synthesis of the complete sets of 18 novel 3- and 21-monosulfates and their double-conjugated form of tetrahydrocortisol (THF), tetrahydro-11-deoxycortisol (THS), and tetrahydrocortisone (THE) in the 5 α- and 5 β-series. The principal reactions involved are: (1) selective protection of a specific hydroxy group in substrates; (2) catalytic hydrogenation at C-5 of Δ4-3-ketosteroids with 10% Pd(OH) 2/C to yield 3-oxo-5 β-steroids and reductive allomerization with 10% Pd/C to yield 3-oxo-5 α-isomers; (3) reduction of the resulting 3-oxo-5 β- and 3-oxo-5 α-steroids to the corresponding 3 α-hydroxy-compounds with Zn(BH4)2 and K-Selectride, respectively; and (4) sulfation of hydroxy groups at C-3 and/or C-21 in the tetrahydrocorticosteroid derivatives with sulfur trioxide-triethylamine complex.
- Okihara, Rika,Mitamura, Kuniko,Hasegawa, Maki,Mori, Megumi,Muto, Akina,Kakiyama, Genta,Ogawa, Shoujiro,Iida, Takashi,Shimada, Miki,Mano, Nariyasu,Ikegawa, Shigeo
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experimental part
p. 344 - 353
(2011/02/22)
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- Biotransformation of corticosteroids by Penicillium decumbens ATCC 10436
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The biotransformation of a series of corticosteroids by the fungus Penicillium decumbens ATCC 10436 has been investigated. Conversion to the corresponding 5α-dihydroxteroid was observed for all the Δ4-3-ketosteroids studied with the exception of deoxycorticosterone, which was converted to a Δ14-diene. Deoxycorticosterone acetate was, however, converted to a 5α- dihydro product concomitant with ester hydrolysis. Other substrates carrying a C-21 acetoxy group were also hydrolyzed to the alcohol. In two cases (resulting from deoxycorticosterone acetate and 11-deoxycortisone) the 5α- 3-keto-product was further reduced to the 3β-alcohol. No reduction of δ14-dienes was observed.
- Holland, Herbert L.
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p. 646 - 649
(2007/10/02)
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- The scarlet letter: Reichstein's substance S. A comparison of the angiostatic properties of 5α-tetrahydro S and 5β-tetrahydro S
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5β-Tetrahydro-Reichtein's Substance S (3α, 5β-THS) from different sources yielded variable bioassays activity in the chick chorio-allantoic membrane assay system. Physical characterization showed impure products. Synthesis of this compound by two different routes yielded active and inactive 3α,5β-THS. Of the other two epimers, 3β,5β-THS (epi-THS) and 3α,5α-THS (allo-THS), only the latter was active. These results suggest that the impurities present in 3α,5β-THS synthesized by reduction of the α,β-unsaturated ketone of Substance S might be either or both the epi- lallo-epimers (3β,5β-THS and 3α,5α-THS, respectively), with only the latter contributing the positive angiostatic activity to the mixture. Of the two synthetically derived compounds, only the latter was shown to maintain the activity, whereas 3α,5β-THS was not antiangiogenic.
- Hadd, Harry E.
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p. 650 - 655
(2007/10/02)
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