- 6-Oxoestradiols from estradiols: Exploiting site selective metalation of aralkyl systems with superbases
-
3-O-Protected estradiol derivatives undergo metalation at C-6 when exposed to a fourfold excess of the reagent consisting of an equimolar mixture of lithium diisopropylamide and potassium 1,1-dimethylpropoxide (3 h, THF, -78°C). The metalated intermediates can be oxidized by quenching with trimethyl borate followed by treatment with hydrogen peroxide, thus allowing the introduction of a 6-hydroxy group into the estradiol framework. Further oxidation of the 6-hydroxy group gives O-protected 6-oxoestradiols.
- Tedesco,Fiaschi,Napolitano
-
-
Read Online
- The hetero-cubane structures of the heavy alkali metal: Tert -amyloxides [MOCMe2Et]4 (M = K, Rb, Cs)
-
A series of alkali metal (Li-Cs) alkoxides of tert-pentanol (1,1-dimethylpropan-1-ol) have been prepared by reaction of the corresponding metal with the alcohol in n-hexane or n-heptane. The compounds were purified by vacuum sublimation and crystallised in n-hexane to produce crystals suitable for single-crystal X-ray diffraction studies. The structures of the potassium, rubidium, and caesium compounds revealed tetrameric units with additional intra- and intermolecular interactions between the metal atom and alkoxide methyl groups, increasing with the size of the metal involved.
- Kaiser, Maximillian,Klett, Jan
-
supporting information
p. 12582 - 12586
(2018/09/27)
-
- Antiangiogenic agents
-
Compositions and methods for treating mammalian diseases or conditions characterized by undesirable angiogenesis by administering an effective amount of a compound of the formulae: wherein Ra is selected from —OCH3, —OCH2CH3 or —CCCH3; and Z is selected from >C(H)—OH, >C(H)—O-alkyl, >C(H)—O-sulfamate, where alkyl is a linear, branched and/or cyclic hydrocarbon chain comprising 1 to 10 carbons.
- -
-
Page/Page column 15
(2008/06/13)
-
- Method for producing alkali metal alcoholates
-
The invention relates to a method for producing alkali metal alcoholates by reacting alcohol with alkali metal in an aprotic, organic solvent in the presence of an H acceptor such as e.g. isoprene, butadiene, styrene or methyl styrene.
- -
-
-