- Method for preparing 7-acetyl paclitaxel
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The invention discloses a method for preparing 7-acetyl paclitaxel. The method comprises the following steps: 1, acetylizing the seventh position and the tenth position of 10-Dab used as a raw material to prepare an intermediate 1; 2, carrying out a conde
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Paragraph 0024; 0028-0030; 0034; 0035; 0036; 0039-0041
(2018/03/28)
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- Bromotrifluoromethoxy compound and synthetic method thereof
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According to the invention, a series of trifluoromethoxy reagent precursors are synthesized, and trifluoromethoxy silver with high activity can be obtained under the condition of an activating reagent. By the utilization of the idea, a bromotrifluorometho
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Paragraph 0105; 0106
(2017/08/27)
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- Silver-mediated oxidative aliphatic C-H trifluoromethylthiolation
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The first example of a practical and direct trifluoromethylthiolation reaction of unactivated aliphatic C-H bonds employs a silver-based reagent. The reaction is operationally simple, scalable, and proceeds under aqueous conditions in air. Furthermore, its broad scope and good functional-group compatibility were demonstrated by applying this method to the selective trifluoromethylthiolation of natural products and natural-product derivatives.
- Guo, Shuo,Zhang, Xiaofei,Tang, Pingping
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supporting information
p. 4065 - 4069
(2015/03/30)
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- Point mutations (Q19P and N23K) increase the operational solubility of a 2α-o-benzoyltransferase that conveys various acyl groups from CoA to a taxane acceptor
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Two site-directed mutations within the wild-type 2-o-benzoyltransferase (tbf) cDNA, from Taxus cuspidata plants, yielded an encoded protein containing replacement amino acids at Q19P and N23K that map to a solvent-exposed loop region. The likely significant changes in the biophysical, properties invoked by these mutations caused the overexpressed, modified TBT (mTBT) to partition into the soluble enzyme fraction about 5-fold greater than the wild-type enzyme. Sufficient protein could now be acquired to examine the scope of the substrate specificity of mTBT by incubation with 7,13-O,O-diacetyl-2-Odebenzoylbaccatin III that was mixed individually with various substituted benzoyls, alkanoyls, and (E)-butenoyl CoA donors. The mTBT catalyzed the conversion of each 7,13-O,O-diacetyl-2-O-debenzoylbaccatin III to several 7,13-O,O-diacetyl-2O- acyl-2-O-debenzoylbaeeatin III analogues. The relative catalytic efficiency of mTBT with the 7,13-O,O-diacetyl-2-Odebenzoyl surrogate substrate and heterole carbonyl CoA substrates was slightly greater than with the natural aroyl substrate benzoyl CoA, while substituted benzoyl CoA thioesters were less productive. Short-chain hydrocarbon carbonyl and cyclohexanoyl CoA thioesters were also productive, where C4 substrates were transferred by mTBT with ~10- to 17-fold greater catalytic efficiency compared to the transfer of benzoyl. The described broad specificity of mTBT suggests that a plethora of 2-O-acyl variants of the antimitotic paclitaxel can be assembled through biocatalytic sequences.
- Nawarathne, Irosha N.,Walker, Kevin D.
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experimental part
p. 151 - 159
(2010/07/06)
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- CONVERSION 9-DIHYDRO-13-ACETYLBACCATIN III TO 10-DEACETYLBACCATIN III
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The present invention relates to a process is provided for the conversion of 9-dihydro-13-acetylbaccatin to 10-deacetylbaccatin III. The process includes four specific interrelated steps. The first step involves protecting the 7-hydroxyl group of 9-dihydro-13-acetylbaccatin and converting that 7-hydroxyl-protected 9-dihydro-13-acetylbaccatin to 7, 13-diacetyl-9-dihydrobaccatin III. The second step involves reacting that 7, 13-diacetyl-9-dihydrobaccatin III with 4-methylmorpholine N-oxide in a suitable solvent and oxidizing that reaction product to yield 7, 13-diacetylbaccatin. The third step involves deacetylating that 7, 13-diacetyl-9-dihydrobaccatin III to yield 7-acetylbaccatin III. The fourth and final step involves converting that 7-acetylbaccatin III to 10-deacetylbaccatin III.
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Page/Page column 9
(2008/06/13)
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- CHEMICAL STUDIES OF 10-DEACETYL BACCATIN III. HEMISYNTHESIS OF TAXOL DERIVATIVES.
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The chemical reactivities of 10-deacetyl baccatin III and of baccatin III, two natural products extracted from Taxus baccata L., were studied with aim of synthesizing taxol analogues having a modified side-chain at C-13, thereby restoring good binding to tubulin.
- Gueritte-Voegelein, F.,Senilh, V.,David, B.,Guenard, B.,Potier, P.
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p. 4451 - 4460
(2007/10/02)
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