- Regio- and stereoselective methods for the conversion of (2S,3R)-β-phenylglycidic acid esters to taxoids and other enantiopure (2R,3S)-phenylisoserine esters
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A novel efficient method was proposed for the synthesis of enantiopure precursors of taxane-containing cytostatics, i.e., methyl esters of (2R,3S)- and (2S,3R)-N-benzoylphenylisoserine and similar taxoid esters. The method is based on the regio- and stereoselective hydrobromolysis of the corresponding trans-β-phenyl glycidate enatiomers, consecutive reactions of O-acylcarbamoylation of the obtained 3-bromohydrins, intramolecular cyclization to 4-phenyloxazolidin-2-one-5-carboxylic acid derivatives, and oxazolidinone ring opening.
- Afon'Kin,Kostrikin,Shumeiko,Popov,Matveev,Matvienko,Zabudkin
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p. 2149 - 2162
(2013/10/01)
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- VERSUCHE ZUR DARSTELLUNG VON α-CHLOR-N-SULFINYLAMINEN
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The α-chloro-α-alkoxy-N-sulfinylamines are thought to be highly reactive in pericyclic reactions.To investigate this assumption, we have prepared one example for this class of compounds, 2, it splits off CH3Cl during Diels-Alder reaction to give the adduct of Cl3CCONSO.
- Schwoebel, Alfred,Lux, Rudolf,Kresze, Guenter
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- Oligomerization of Trichloroacetonitrile (TCA) by Metal Salts
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A CN bond was found to transform into a C=N bond under such a mild conditions as to mix trichloroacetonitrile, metal salts and methanol at 20 deg C.Ni(II) and Co(II) gave dimeric ring complexes and Mn(II) gave amidine, aminotriazine and brown powder.The aminotriazine was isolated as unstable liquid which spontaneously transformed into the crystal.A trimer structure was proposed for the liquid.In anhydrous systems, any oligomerization did not occur, so water was concluded to participate in the initiation.Keywords - trichloroacetonitrile; metal salt; methanol; nitrile; imino bond; dimeric ring complex; amidine; aminotriazine; trimer
- Suematsu, Kazumi
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p. 291 - 294
(2007/10/02)
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- Orthoamides, XXXV. - Preparation of O,N-Functional Trisubstituted Acetonitriles
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Trichloroacetonitrile (7) reacts with molar amounts of alcoholates in alcohols to give mixtures of orthocarbonates 10 and trichloroacetimidates 9.The action of 7 on 3 moles of sodium ethoxide in heptane affords triethoxyacetonitrile 3b among other products, such as 9b, 10b and the imidate 12.The nitrile 3a can be obtained from 7 and sodium methoxide in ether in moderate yields. - The orthocarbonic acid derivatives 10b, 20a and 21a are transformed by acyl cyanides into the nitriles 3b, 4a, and 5a, respectively.N,N,N',N',N'',N''-hexamethylguanidinium cyanide (23a) is f ormed in the reaction of 22 with acetyl cyanide. - The salts 30a-32a react with alkali cyanides to form the nitriles 3b, 4a, and 5a, respectively.The nitrile 2a transfers cyanide ions to the carbenium ions 30a and 31a to yield the nitriles 3b and 4a, respectively.
- Kantlehner, Willi,Maier, Thomas,Kapassakalidis, Joannis J.
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