Direct, stereoselective synthesis of the protected paclitaxel (taxol) side chain and high-yield transformation to paclitaxel

1994 ◽  
pp. 2591 ◽  
Author(s):  
Alice M. Kanazawa ◽  
Jean-No�l Denis ◽  
Andrew E. Greene
Keyword(s):  
Stereoselective Synthesis ◽  
High Yield ◽  
Side Chain

Enantioselective synthesis of 1-aryl-2-propenylamines: a new approach to a stereoselective synthesis of the Taxol® side chain

2004 ◽  
Vol 15 (6) ◽  
pp. 941-949 ◽  
Author(s):  
Daniele Castagnolo ◽  
Silvia Armaroli ◽  
Federico Corelli ◽  
Maurizio Botta
Keyword(s):  
Stereoselective Synthesis ◽  
Enantioselective Synthesis ◽  
Side Chain ◽  
New Approach

Stereoselective Synthesis of Cholesteryl Derivatives Bearing a Chiral Allenic Group in the Side Chain

Synthesis ◽  
1989 ◽  
Vol 1989 (02) ◽  
pp. 93-97 ◽  
Author(s):  
Alain Burger ◽  
Charles Hetru ◽  
Bang Luu
Keyword(s):  
Stereoselective Synthesis ◽  
Side Chain

scholarly journals Effect of Fe Additives on the Catalytic Performance of Ion-Exchanged CsX Zeolites for Side-Chain Alkylation of Toluene with Methanol

Catalysts ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 829 ◽  
Author(s):  
Zhang ◽  
Yuan ◽  
Miao ◽  
Li ◽  
Shan ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Catalytic Performance ◽  
High Yield ◽  
Side Chain ◽  
Impregnation Method ◽  
Basic Sites ◽  
Lewis Acidic Sites ◽  
X Zeolite ◽  
Acidic Sites ◽  
Negative Effect

The side-chain alkylation of toluene with methanol was investigated over some Fe-modified Cs ion-exchanged X zeolite (CsX) catalysts prepared via the impregnation method using different iron sources. The absorption/activation behaviors of the reactants on the surface of the catalysts were studied by in situ Fourier-transform infrared (FT-IR) spectroscopy and temperature programmed desorption (TPD) mass measurements. Modification of CsX with a small amount of FeCl3 could result in a considerable decrease in catalytic activity, due mainly to the remarkable decrease in the density of acidic and basic sites of the catalysts. Interestingly, the Fe(NO3)3-modified CsX with an optimum Fe loading of 0.15 wt.% shows improved catalytic activity and high yield compared to the side-chain alkylation products. Modification of CsX with Fe(NO3)3 could also result in a decrease in basic sites of the catalyst. However, such a change does not bring an obvious negative effect on the adsorption/activation of toluene, while it could effectively inhibit the generation of the undesired bidentate formate. Furthermore, the introduced FeOx species (derived from the decomposition of Fe(NO3)3) may also act as new Lewis acidic sites to participate in the activation of methanol and to stabilize the formed active intermediates (i.e., unidentate formate). Therefore, modification of CsX with a suitable amount of Fe(NO3)3 may adjust its adsorption/activation ability for reagents by changing the acid–base properties of the catalyst, which can finally enhance the catalytic performance for the side-chain alkylation of toluene with methanol.

A Practical and Stereoselective Synthesis of Taxol Side Chain

2003 ◽  
Vol 33 (5) ◽  
pp. 723-728 ◽  
Author(s):  
Zhongqiang Zhou ◽  
Xingguo Mei
Keyword(s):  
Stereoselective Synthesis ◽  
Side Chain

An Efficient Two-Step Protocol for the Isoprenylation of Xanthone at the C2 Position Starting from 1-Fluoroxanthone Derivative

Synlett ◽  
2020 ◽  
Vol 31 (14) ◽  
pp. 1423-1429
Author(s):  
Takashi Matsumoto ◽  
Yuuki Fujimoto ◽  
Chisato Furukawa ◽  
Kanae Takahashi ◽  
Miho Mochizuki ◽  
...  
Keyword(s):  
Silica Gel ◽  
Room Temperature ◽  
Claisen Rearrangement ◽  
High Yield ◽  
Side Chain ◽  
Snar Reaction

The SNAr reaction of 1-fluoroxanthone derivatives with alkoxide of 1,1-dimethylallyl alcohol cleanly afforded the corresponding ethers, which have thus far been unavailable. The obtained ethers underwent the Claisen rearrangement at room temperature by treatment with silica gel in toluene. This two-step protocol provides expeditious and high-yield access to xanthones possessing isoprenyl or the related allylic side chain at the C2 position.

Experiments Directed Towards the Synthesis of Anthracyclinones. XXVIII. Titanium(IV)- and Tin(IV)-Mediated Cyclizations of ortho-Methallyl-Substituted Homochiral Dioxans

1996 ◽  
Vol 49 (6) ◽  
pp. 677 ◽  
Author(s):  
RC Cambie ◽  
KC Higgs ◽  
JJ Rustenhoven ◽  
PS Rutledge
Keyword(s):  
Lewis Acid ◽  
Major Product ◽  
Metal Chloride ◽  
High Yield ◽  
Side Chain

Metal chloride cyclizations of the 4-demethoxy anthraquinonyl 1′,3'-dioxan (6) are highly diastereoselective , giving 9-chloro-9-methylanthracyclinones in high yield. The selectivity is inversely proportional to the strength of the Lewis acid, with the mild Lewis acid tin(IV) chloride/ dimethylformamide affording an 82% yield of the diastereomer (21). The predominant products have a (7S) configuration and a trans relationship between the C7 side chain and the 9-chloro substituent. Cyclization of the analogous dimethoxy 1′,3′-dioxan (4) with tin(IV) chloride/ dimethylformamide is considerably less selective, but the major product also has a (7S)-trans stereochemistry. Titanium(IV) chloride effects stereorandom cyclization of (4).

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