- Synthesis method of paclitaxel side chain and analogs thereof (by machine translation)
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The invention discloses a synthesis method of a taxol side chain ((4S, 5R) -3 - benzoyl -2 - (4 - methoxyphenyl) -4 - phenyl -5 - oxazoline carboxylic acid) shown as a formula (f) and a series of reactions such as epoxidation, methyl esterification, ammonolysis, ester hydrolysis, condensation, configuration overturning, condensation and hydrolysis as well as analogues thereof. The invention discloses a synthesis method of the taxol side chain ((4S 5R) -3 -benzoyl -2 - (4 - methoxyphenyl) -4 - phenyl -5 - oxazoline carboxylic acid) and the like. The method has the advantages of short reaction time, high yield, good chiral selectivity, suitability for industrial production and the like. (by machine translation)
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- Efficient enantioselective synthesis of α-hydroxy-β-amino acids using the Claisen and Curtius rearrangements
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Highly enantioselective and facile synthesis of α-hydroxy-β- amino acids has been achieved using the Claisen and Curtius rearrangements as key reactions. Chiral allylic alcohols were employed, which can be prepared by asymmetric catalysis in both E- and Z
- Jung, Doo Young,Kang, Sol,Chang, Sukbok,Kim, Yong Hae
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- Efficient asymmetric synthesis of 2,3-diamino-3-phenylpropanoic acid derivatives
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An efficient, stereoselective synthesis of selectively-protected anti and syn, methyl 2-amino-3-(Boc-amino)-3-phenylpropanoate is described. Preparation of syn β-acetylamino-α-hydroxy ester was from isopropyl cinnamate via an acetamide-based Sharpless ami
- Lee, Sang-Hyeup,Yoon, Juyoung,Chung, Seung-Hwan,Lee, Yoon-Sik
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p. 2139 - 2145
(2007/10/03)
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- Application of Yeast-Catalyzed Reductions to Synthesis of (2R,3S)-Phenylisoserine
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A simple synthesis of (2R,3S)-phenylisoserine, a precursor of the C-13 side chain of Taxol (paclitaxel), utilising yeast-catalyzed reduction to generate a second chiral centre is reported.This short enantioselective series of transformations can be readily adapted to large scale production of a variety of N-substituted paclitaxel analogues.
- Kearns, Jeff,Kayser, Margaret
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p. 2845 - 2848
(2007/10/02)
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- Synthesis of β-amino α-hydroxy carboxylic esters from oxiranecarboxylic esters
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3-Aryl-3-azido-2-hydroxypropanoic esters, prepared from the corresponding 3-aryl-oxirane-2-carboxylic esters by ring opening with sodium azide, were reduced with tin(II) chloride dihydrate in methanol to give 3-amino-3-aryl-2-hydroxypropanoic esters in good yields.Under these conditions, halogen substituents in the aromatic rings were not affected.The nitro group, however, was partially reduced to the amino group.Treatment of aliphatic oxirane-2-carboxylic esters with acetonitrile in the presence of boron trifluoride etherate led to regiospecific formation of 2,4-dialkyl-2-oxazoline-5-carboxylic esters, resulting from reaction of the nitrile at C3.Acidic hydrolysis of these oxazoline-5-carboxylic esters gave the corresponding 3-(acylamino)-2-hydroxy carboxylic esters.With these two complementary methods, both aryl- and alkyl-substituted β-amino α-hydroxy acid derivatives are accessible.
- Legters, Johan,Dienst, Erik van,Thijs, Lambertus,Zwanenburg, Binne
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- Highly stereoselective synthesis of α-hydroxy β-amino acids through β-lactams: Application to the synthesis of the taxol and bestatin side chains and related systems
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Formation of α-hydroxy β-lactams, followed by chemical elaboration at C4 and further β-lactam cleavage afforded functionalised α-hydroxy β-amino acids or their derivatives in a highly stereoselective manner.
- Palomo,Arrieta,Cossio,Aizpurua,Mielgo,Aurrekoetxea
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p. 6429 - 6432
(2007/10/02)
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- CHEMO-ENZYMATIC SYNTHESIS OF ALL ISOMERIC 3-PHENYLSERINES AND -ISOSERINES
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The synthesis of all isomers of 3-phenylserines and 3-phenylisoserines in enantiomerically pure form is presented.Diastereomerically pure educts (threo/erythro-2-azido-3-butanoyloxy-3-phenyl-propionic esters, threo/erythro-3-azido-2-butanoyloxy-3-phenylpropionic esters, threo-2-butanoylamino-3-butanoyloxy-3-phenylpropionic ester, erythro-3-butanoylamino-2-butanoyloxy-3-phenyl-propionamide) were prepared from cinnamic acid derivatives or via aldol condensations of benzaldehyde and suitable enolates in few steps.These racemates were resolved with lipases from Candida cylindracea (CC) and Pseudomonas fluorescens (P) and the obtained products were hydrogenated to 3-phenylserines and -isoserines.The influence of the acyl group in the enzymatic resolution of erythro-3-azido-2-acyloxy-3-phenylpropionic esters was investigated.
- Hoenig, H.,Seufer-Wasserthal, P.,Weber, H.
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p. 3841 - 3850
(2007/10/02)
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