- A convenient synthesis of the paclitaxel side-chain via a diastereoselective Staudinger reaction
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The N-benzylidene dexivative of (S)-(-)-1-(p-mathoxyphenyl)propyl-1- amine, obtained by a new resolution procedure, exhibits moderate selectivity in the reaction with 2-acetoxyketene; the (S)-(-)-1-(p-methoxyphenyl)propyl group can be oxidatively cleaved from the resultant β-lactam, an important precursor for taxane semi-synthesis.
- Brown, Stephen,Jordan, Allan M.,Lawrence, Nicholas J.,Pritchard, Robin G.,McGown, Alan T.
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- Asymmetric synthesis of 3-amino-2-hydroxyalkanoates by Mannich reaction of menthyl acetate with imines and subsequent oxidation
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Lithium amide-assisted Mannich-type reaction of menthyl acetate-derived lithium enolate with PMP-arylaldimines and subsequent in situ oxidation with oxaziridine gave syn-3-amino-3-aryl-2-hydroxypropanoates with high syn-selectivity and diastereoselectivit
- Hata, Seiji,Tomioka, Kiyoshi
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p. 8514 - 8520
(2008/02/09)
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- Beta-lactam synthesis
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The present invention is directed to a process for the preparation of β-lactams. Generally, an imine is cyclocondensed with a ketene acetal or enolate to form the β-lactam product in a "one pot" synthesis, this process is generally performed at a higher temperature than conventional processes.
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Page/Page column 10
(2008/06/13)
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- Studies on stereoselective [2+2] cycloadditions between N,N-dialkylhydrazones and ketenes
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Staudinger-like cycloadditions between chiral, non-racemic N,N-dialkylhydrazones 1 and functionalized ketenes constitute an efficient methodology for the stereoselective construction of the β-lactam ring. The potential for fine tuning of the dialkylamino
- Martin-Zamora, Eloisa,Ferrete, Ana,Llera, Jose M.,Munoz, Jesus M.,Pappalardo, Rafael R.,Fernandez, Rosario,Lassaletta, Jose M.
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p. 6111 - 6129
(2007/10/03)
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- β-lactams, methods for the preparation of taxanes, and sidechain-bearing taxanes
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Novel β-lactams finding utility as intermediates in the preparation of sidechain-bearing taxanes such as taxol and taxol derivatives. The present invention also relates to novel methods of coupling β-lactams to form such sidechain-bearing taxanes, and to novel sidechain-bearing taxanes.
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Page column 11
(2010/01/30)
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- β-lactams, methods for the preparation of taxanes, and sidechain-bearing taxanes
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Novel β-lactams finding utility as intermediates in the preparation of sidechain-bearing taxanes such as taxol and taxol derivatives. The present invention also relates to novel methods of coupling β-lactams to form such sidechain-bearing taxanes, and to
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Page column 11
(2010/01/30)
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- N,N-dialkylhydrazones as the imine component in the Staudinger-like [2+2] cycloaddition to benzyloxyketene
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To overcome the limitations of using unstable imines in Staudinger cycloadditions to ketenes, aldehyde N,N-dialkylhydrazones 1 were used as stable imines. This strategy and a fine tuning of the auxiliary result in a straightforward synthesis of cycloadducts 2, deprotected β-lactams 3, and isoserines 4 (see scheme: a) Et3N, toluene, Δ; b) 1. magnesium monoperoxyphthalate, 2. H2, Pd/C; c) H+).
- Fernandez, Rosario,Ferrete, Ana,Lassaletta, Jose M.,Llera, Jose M.,Martin-Zamora, Eloisa
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p. 831 - 833
(2007/10/03)
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- A new synthetic route to (3R,4S)-3-hydroxy-4-phenylazetidin-2-one as a taxol side chain precursor
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A new synthetic route to (3R,4S)-3-hydroxy-4-phenylazetidin-2-one, an important precursor for the paclitaxel side chain, has been developed using intramolecular cyclization of N-(p-methoxyphenyl) (2S,3R)-2-acetoxy-3-bromo- 3-phenylpropionamide which can be easily obtained by catalytic asymmetric dihydroxylation of N-(p-methoxyphenyl)-trans-cinnamide, followed by bromoacetylation.
- Song, Choong Eui,Lee, Sung Woo,Roh, Eun Joo,Lee, Sang-Gi,Lee, Won-Ku
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p. 983 - 992
(2007/10/03)
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- Anti-tumor compounds, pharmaceutical compositions, methods for preparation thereof and for treatment
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The present invention is directed to novel taxanes useful as chemotherapeutic agents or their precursors. Processes for preparing the novel taxanes include coupling reactions, in the presence of a base, of baccatin of formula (III) or (IV) STR1 with β-lac
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- Anti-tumor compounds, pharmaceutical compositions, methods for preparation thereof and for treatment
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The present invention is directed to novel taxanes useful as chemotherapeutic agents or their precursors. Processes for preparing the novel taxanes include coupling reactions, in the presence of a base, of baccatin of formula (III) or (IV) STR1 with β-lac
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- Process for the production of chiral hydroxy-β-lactams and hydroxyamino acids derived therefrom
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The reaction between a hydroxyacetic acid derivative bearing an oxygen protecting group and a chiral auxiliary group and an imine produces chiral β-lactams. Hydrolysis of the chiral β-lactams produces chiral amino acid analogs.
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- A highly efficient route to taxotere by the β-lactam synthon method
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Taxotere, a highly promising anticancer drug, is synthesized through an efficient coupling of 7,10-diTroc-10-deacetylbaccatin III with enantiomerically pure (3R,4S)-1-tBOC-3-EEO- 4-phenylazetidin-2-one which is obtained via chiral ester enolate - imine cyclocondensation.
- Ojima, Iwao,Sun, Chung Ming,Zucco, Martine,Park, Young Boon,Duclos, Olivier,Kuduk, Scott
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p. 4149 - 4152
(2007/10/02)
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- Chemoenzymatic Synthesis of the C-13 Side Chain of Taxol: Optically Active 3-Hydroxy-4-phenyl β-Lactam Derivatives
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Enantiomerically pure 3-hydroxy-4-phenyl β-lactam derivatives have been successfully prepared via enantioselective hydrolyses and transesterifications of racemic esters and alcohols respectivily catalyzed by bacterial lipases.These lipases also catalyzed highly enantioselective cleavage of the β-lactam ring of (+/-)-10 to yield derivatives of (2R,3S)-phenylisoserine in high enantiomeric excess.The resolved enantiomers are important intermediates in the synthesis of the C-13 side chain of taxol.
- Brieva, Rosario,Crich, Joyce Z.,Sih, Charles J.
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p. 1068 - 1075
(2007/10/02)
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- New and efficient approaches to the semisynthesis of taxol and its C-13 side chain analogs by means of β-lactam synthon method
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Highly efficient chiral ester enolate-imine condensation giving 3-hydroxy-4-aryl-β-lactams with excellent enantiomeric purity is successfully applied to the asymmetric synthesis of the enantiomerically pure taxol C-13 side chain, N-benzoyl-(2R,3S)-3-phenyl-isoserine and its analogs. (3R,4S)-N-benzoyl-3-(1-ethoxyethoxy)-4-phenyl-2-azetidinone readily derived from the 3-hydroxy-4-phenyl-β-lactam is coupled with protected baccatin IIIs, followed by deprotection to give optically pure taxol and 10-deacetyl-7,10-bis(Troc)-taxol in good yields. Fully assigned 1H, 13C, and 2D (COSY and HETCOR) NMR spectra of taxol thus synthesized are shown and discussed.
- Ojima, Iwao,Habus, Ivan,Zhao, Mangzhu,Zucco, Martine,Park, Young Hoon,Sun, Chung Ming,Brigaud, Thierry
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p. 6985 - 7012
(2007/10/02)
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- Synthesis of biologically active taxol analogues with modified phenylisoserine side chains
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Taxol (1) is a highly potent antitumor agent, exerting its mechanism of action by promoting the assembly of stable microtubules in cells. We are reporting on the first synthesis and biological evaluation of taxol derivatives with substituted phenyl rings
- Georg,Cheruvallath,Himes,Mejillano,Burke
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p. 4230 - 4237
(2007/10/02)
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- Method for preparation of taxol using β-lactam
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A β-lactam of the formula: STR1 wherein R1 is aryl, substituted aryl, alkyl, alkenyl, or alkynyl; R2 is hydrogen, alkyl, acyl, acetal, ethoxyethyl, or other hydroxyl protecting group; and R3 is aryl, substituted aryl, alky
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- Efficient and Practical Asymmetric Synthesis of the Taxol C-13 Side Chain, N-Benzoyl-(2R,3S)-3-phenylisoserine, and Its Analogues via Chiral 3-Hydroxy-4-aryl-β-lactams through Chiral Ester Enolate-Imine Cyclocondensation
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A highly efficient chiral ester enolate-imine condensation giving 3-hydroxy-4-aryl-β-lactams with >96percent ee is successfully applied to the asymmetric synthesis of the enantiomerically pure taxol C-13 side chain, N-benzoyl-(2R,3S)-3-phenylisoserine, and its analogues.
- Ojima, Iwao,Habus, Ivan,Zhao, Mangzhu,Georg, Gunda I.,Jayasinghe, Lalith R.
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p. 1681 - 1683
(2007/10/02)
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