Reaction of steroidal 3-keto-19-carboxylic acids and 19-nor steroidal dienones in solutions of iodine in pyridine

Alvarez, Francisco S.; Watt, Alexander N.

doi:10.1021/jo00796a033

Cited by 5 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Oxidation of 17 α -hydroxyestra-4,9-dien-3-one (16) to estra-4,9-diene-3,17-dione : mp 125.2−126.5 °C; lit . mp 130−131 °C; lit . mp 119−121 °C; 13 C NMR δ = 13.45 (q, 18-C), 22.15 (t), 25.42 (t), 26.12 (t), 26.76 (t), 30.94 (t), 31.71 (t), 36.11 (t), 37.26 (t), 38.96 (d, 14-C), 47.74 (s, 13-C), 51.39 (d, 8-C), 122.65 (d, 4-C), 126.42 (s, 10-C), 145.23 (s), 157.07 (s), 199.78 (s, 3-C), 219.95 (s, 17-C).…”

Section: Methodsmentioning

confidence: 99%

Transition-Metal Catalyzed Oxidations. 7. Zirconium-Catalyzed Oxidation of Primary and Secondary Alcohols with Hydroperoxides

1996

View full text Add to dashboard Cite

A new procedure for the oxidation (dehydrogenation) of primary and secondary alcohols employing Zr(O-t-Bu)4 or Zr(O-n-Pr)4/tert-butyl hydroperoxide/3 Å molecular sieves is presented. Secondary alcoholsif not severely sterically hinderedare usually converted quantitatively to the corresponding ketones. Esters or acids can be byproducts in the reaction of primary alcohols. However, the aldehydes are obtained in good yield by lowering the reaction temperature, decreasing the amount of TBHP or replacing TBHP by cumene hydroperoxide (CHP), and/or exchanging the catalyst Zr(O-t-Bu)4 by Zr(O-n-Pr)4 or silica gel-supported Zr(OR) x . A remarkable selectivity of equatorial alcohol groups (e.g., 11 and 13) is observed in contrast to chromium(VI)-based oxidations. Strongly chelating substrates such as furfuryl alcohol (18) or 1,2-diol 25 that prevent hydride transfer in the six-membered transition state A are not converted.

show abstract

Section: Methodsmentioning

confidence: 99%

Transition-Metal Catalyzed Oxidations. 7. Zirconium-Catalyzed Oxidation of Primary and Secondary Alcohols with Hydroperoxides

1996

View full text Add to dashboard Cite

show abstract

“…A stirred solution of 1 (540.8 mg, 2 mmol) in MeOH (80 mL) was heated at 45 • C. DDQ (680.9 mg) was added in one portion and the resulting solution was vigorously stirred for 5 h at 45 • C under nitrogen (N 2 ) atmosphere. After completion of the reaction (TLC control), MeOH was evaporated and the residue was diluted in 300 mL of dichloromethane (CH 2 Cl 2 ), washed with 100 mL of aqueous 10% sodium sulfite (Na 2 SO 3 ), 100 mL of a saturated aqueous solution of sodium hydrogen carbonate (NaHCO 3 ) and 100 mL of water (H 2 O) and dried over anhydrous sodium sulfate (Na 2 SO 4 ), filtered and evaporated under reduced pressure to yield the crude product, which was recrystallized from MeOH to give compound 2 [26,27] as beige crystals (223.5 mg, 42% yield); mp 235.2-237 • C (lit [28] 243-246…”

Section: Synthesis Of 3-hydroxyestra-135(10)9(11)tetraen-17-one (2)mentioning

confidence: 99%

Δ 9,11 -Estrone derivatives as potential antiproliferative agents: synthesis, in vitro biological evaluation and docking studies

Canário¹,

Matias²,

Brito³

et al. 2020

Comptes Rendus. Chimie

View full text Add to dashboard Cite

A series of ∆ 9,11 -estrone derivatives with A-and D-ring modifications has been synthesized and evaluated as antiproliferative agents. The cytotoxicity was assessed in six cell lines (MCF-7, T47-D, LNCaP, HepaRG, Caco-2 and NHDF) by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and a cell cycle distribution analysis was performed by flow cytometry. Some compounds exhibited relevant cytotoxicity, particularly ∆ 9,11 -estrone, which was the most active against HepaRG cells (IC 50 = 6.67 µM). Besides the relevance of the double bond in the C-ring, the presence of a 16E-benzylidene group increased the antiproliferative effect on MCF-7 and T47-D cells. Moreover, the introduction of iodine in positions 2 and 4 of estrone seemed to induce a selective cytotoxicity for HepaRG cells. Flow cytometry experiments evidenced a 34% reduction of HepaRG cell viability after treatment with ∆ 9,11 -estrone and a cell cycle arrest at the G 0 /G 1 phase. Estrogenic activity was also observed for this compound at 0.1 µM in T47-D cells, and molecular docking studies estimated a marked interaction between this compound and the estrogen receptor α.

show abstract

Reductions by Metal Alkoxyaluminum Hydrides. PartII. Carboxylic Acids and Derivatives, Nitrogen Compounds, and Sulfur Compounds

Málek

1988

Organic Reactions

View full text Add to dashboard Cite

In continuation of the previous review on reductions by metal alkoxyaluminum hydrides, this chapter is devoted to reductions of carboxylic acids and their derivatives, open‐chain and heterocyclic nitrogen compounds, and open‐chain and heterocyclic sulfur compounds by alkoxyaluminum hydrides, metal alkoxyaluminum hydrides, and chiral metal alkoxyaluminohydride complexes. Emphasis is placed on the scope, limitations, and the synthetic utility of metal alkoxyaluminum hydrides. Accepted views on reaction mechanisms are mentioned briefly. Discussion of alternative methods of reduction, particularly those using other metal hydrides or complex metal hydrides, is limited to examples of the most important transformations of functional groups; reducing properties of these hydrides and hydride reagents such as borane–dimethyl sulfide, amine boranes, haloboranes, organoboranes, sodium borohydride–pyridine, sodium borohydride–triphenyl borate, sodium borohydride—transition‐metal complexes, potassium triisopropoxyborohydride, and sodium triacyloxyborohydrides have been reported in several papers and reviews. Monographs and reviews summarize reductions with metal alkoxyaluminum hydrides and asymmetric reductions with chiral lithium alkoxyaluminum hydrides and chiral boron reagents.

show abstract

Reaction of steroidal 3-keto-19-carboxylic acids and 19-nor steroidal dienones in solutions of iodine in pyridine

Cited by 5 publications

References 0 publications

Transition-Metal Catalyzed Oxidations. 7. Zirconium-Catalyzed Oxidation of Primary and Secondary Alcohols with Hydroperoxides

Transition-Metal Catalyzed Oxidations. 7. Zirconium-Catalyzed Oxidation of Primary and Secondary Alcohols with Hydroperoxides

Δ 9,11 -Estrone derivatives as potential antiproliferative agents: synthesis, in vitro biological evaluation and docking studies

Reductions by Metal Alkoxyaluminum Hydrides. PartII. Carboxylic Acids and Derivatives, Nitrogen Compounds, and Sulfur Compounds

Contact Info

Product

Resources

About