ChemInform Abstract: A Convenient Synthesis of the Paclitaxel Side-Chain via a Diastereoselective Staudinger Reaction.

ChemInform ◽  
2010 ◽  
Vol 29 (32) ◽  
pp. no-no
Author(s):  
S. BROWN ◽  
A. M. JORDAN ◽  
N. J. LAWRENCE ◽  
R. G. PRITCHARD ◽  
A. T. MCGOWN
Keyword(s):  
Side Chain ◽  
Staudinger Reaction ◽  
Convenient Synthesis

A convenient synthesis of the paclitaxel side-chain via a diastereoselective Staudinger reaction

1998 ◽  
Vol 39 (21) ◽  
pp. 3559-3562 ◽  
Author(s):  
Stephen Brown ◽  
Allan M. Jordan ◽  
Nicholas J. Lawrence ◽  
Robin G. Pritchard ◽  
Alan T. McGown
Keyword(s):  
Side Chain ◽  
Staudinger Reaction ◽  
Convenient Synthesis

scholarly journals Practical synthesis of 4-aryl- and 4-heteroarylazetidin-2-ones: applications in the synthesis of the Taxol® side chain

1994 ◽  
Vol 72 (10) ◽  
pp. 2131-2136 ◽  
Author(s):  
Allan W. Rey ◽  
Robert Droghini ◽  
James L. Douglas ◽  
Purushotham Vemishetti ◽  
Susan D. Boettger ◽  
...  
Keyword(s):  
Side Chain ◽  
Staudinger Reaction ◽  
Protecting Group ◽  
Practical Synthesis

A convenient, high-yielding procedure has been developed for the kilogram-scale synthesis of (±)-cis-3-acetoxy-4-phenylazetidin-2-one (3), a β-lactam that has been used in the semi-synthesis of Taxol®. The Staudinger reaction between hydrobenzamide (5) and acetoxyacetyl chloride in the presence of a base provided the α-benzylideneiminotoluene protected β-lactam 8. Without isolation of the intermediate β-lactam, the protecting group was removed under various reductive or hydrolytic conditions. The overall yields were about 80%. The synthesis of other (±)-cis-4-aryl- and 4-heteroarylazetidin-2-ones by this methodology has also been accomplished. These compounds are of value for the synthesis of 3′-Taxol® side-chain analogs and their preparation demonstrates the generality of this approach.

Convenient preparation of a β-O-4-type lignin model trimer via KOH-catalyzed hydroxymethylation and a new protection method

Holzforschung ◽  
2013 ◽  
Vol 67 (2) ◽  
pp. 129-136 ◽  
Author(s):  
Maarit Lahtinen ◽  
Anssi Haikarainen ◽  
Jussi Sipilä
Keyword(s):  
Model Compound ◽  
Catalytic Amount ◽  
Side Chain ◽  
Hydroxyl Groups ◽  
Chemical Behavior ◽  
Model Compounds ◽  
Protection Method ◽  
Convenient Synthesis ◽  
Lignin Model ◽  
Convenient Preparation

Abstract Lignin, as the second most abundant biopolymer on earth, is one of the targets for plant biorefinery studies. Its complex chemical behavior is frequently studied by dimeric, trimeric, etc. model compounds, preferably with a β-O-4-type structure. In the present study, a convenient synthesis of a β-O-4-type trimeric model compound possessing a free syringylic hydroxyl has been investigated. Two key modifications were in focus: (1) Protection of the aliphatic hydroxyl groups of the starting phenolic dimer prior to the SN2 displacement reaction before introducing the syringylic moiety with 2,2-dimethoxypropane. (2) The hydroxymethylation step to introduce the full side chain moiety. When this reaction was performed in dioxane/water in the presence of a catalytic amount of KOH instead of K2CO3, the formation of a side product via dehydration was markedly reduced. In addition, a convenient method for introducing an α,β-epoxide structure in acetophenone is recommended.

Pterins. VIII. The absolute configuration at C 6 of natural 2-Amino-6-[(1'R,2'S)- 1',2'-dihydroxypropyl]-5,6,7,8-tetrahydropteridin-4(3H)-one (L-erythro-5,6,7,8-tetrahydrobiopterin)

1982 ◽  
Vol 35 (4) ◽  
pp. 785 ◽  
Author(s):  
WLF Armarego ◽  
P Waring ◽  
B Paal
Keyword(s):  
Hydrochloric Acid ◽  
Absolute Configuration ◽  
Side Chain ◽  
Methyl Group ◽  
Convenient Synthesis ◽  
The Absolute

The conformation of the side chain of 5,6,7,8-tetrahydrobiopterint (6) in 0.5 M DCl/D2O is predominantly quasi-equatorial (deduced from 3J (13C4a, 1H6) 1.1 HZ), and is the same as that of the methyl group in 2-methyl-1,2,3,4-tetrahydroquinoxaline and in 2-amino-6-methyl-5,6,7,8-tetrahydropteridin-4(3H)-one in the same solvent. Because (-)-(2S)-2-methyl-1,2,3,4-tetrahydroquinoxaline(4) and (-)-(6S)-2-amino-6-methyl-5,6,7,8-tetrahydropteridin-4(3H)-one (5) have the same conformation and negative c.d. spectra (O 248 nm and 263 nm respectively) as does the natural 5,6,7,8, tetrahydrobiopterin (O minimum at 265 nm) in 0.1 M hydrochloric acid, then the absolute conformations of the tetrahydropyrazine rings and the absolute configurations at the chiral centres C2, C6, and C6 of compounds (4), (5) and (6) respectively are the same. Hence the absolute configuration at C6 in natural 5,6,7,8 tetrahydrobiopterin is R.� A convenient synthesis of biopterin on a gram scale is described.

ChemInform Abstract: Convenient Synthesis of Fluorenylmethyl-Based Side Chain Derivatives of Glutamic and Aspartic Acids, Lysine, and Cysteine.

ChemInform ◽  
1990 ◽  
Vol 21 (28) ◽  
Author(s):  
F. ALBERICIO ◽  
E. NICOLAS ◽  
J. RIZO ◽  
M. RUIZ-GAYO ◽  
E. PEDROSO ◽  
...  
Keyword(s):  
Side Chain ◽  
Convenient Synthesis ◽  
Derivatives Of
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