Use of insoluble polymer supports in organic synthesis. 9. Synthesis of unsymmetrical carotenoids on solid phases

1977 ◽  
Vol 42 (19) ◽  
pp. 3203-3205 ◽  
Author(s):  
Clifford C. Leznoff ◽  
Wolodymyr Sywanyk
Keyword(s):  
Organic Synthesis ◽  
Polymer Supports ◽  
Insoluble Polymer ◽  
Solid Phases

The use of polymer supports in organic synthesis. V. The preparation of monoacetates of symmetrical diols

1976 ◽  
Vol 54 (6) ◽  
pp. 935-942 ◽  
Author(s):  
Thomas M. Fyles ◽  
Clifford C. Leznoff
Keyword(s):  
Organic Synthesis ◽  
Acetyl Chloride ◽  
Methyl Benzoate ◽  
Styrene Copolymer ◽  
Polymer Supports ◽  
Acid Cleavage ◽  
Insoluble Polymer

A 2% cross-linked divinylbenzene–styrene copolymer was directly lithiated with n-butyllithium in the presence of N,N,N′,N′-tetramethylethylenediamine. The lithiated polymer on reaction with a benzophenone gave an insoluble polymer-bound trityl alcohol. Further reaction with acetyl chloride gave a polymer-bound trityl chloride which, on treatment with the primary symmetrical diols 1,10-decanediol, 1,7-heptanediol, and 1,4-butanediol, gave mostly symmetrical diols monoblocked by insoluble polymer-bound trityl groups. Acetylation followed by acid cleavage from the polymer gave the monoacetates of 1,10-decanediol, 1,7-heptanediol, and 1,4-butanediol and some recovered diols. The recovered polymer can be efficiently recycled. The quantity of recovered diol was related to the problem of 'double-binding' of the symmetrical diols to the polymer-bound trityl groups. The extent of 'double-binding' could be greatly reduced by the use of polymer-bound trityl chloride prepared via the lithiated polymer and methyl benzoate or phosgene.

scholarly journals The Use of Polymer Supports in Organic Synthesis. II. The Syntheses of Monoethers of Symmetrical Diols

1973 ◽  
Vol 51 (15) ◽  
pp. 2452-2456 ◽  
Author(s):  
Jack Y. Wong ◽  
Clifford C. Leznoff
Keyword(s):  
Organic Synthesis ◽  
Support System ◽  
Functional Group ◽  
Polymer Support ◽  
Reaction Conditions ◽  
Polymer Supports ◽  
Unique Method ◽  
Insoluble Polymer

An insoluble polymer support system was used as a unique method of blocking one functional group of a completely symmetrical difunctional compound. The monotetrahydropyranyl and monotrityl ethers of the symmetrical diols, HO—(CH2)n—OH, where n = 2,4,6,8, and 10, were prepared. Reaction conditions for the preparation of the monotetrahydropyranyl ether of 1,10-decanediol were optimized.

scholarly journals 1999 Alfred Bader Award Lecture From early developments in multi-step organic synthesis on solid phases to multi-nuclear phthalocyanines

2000 ◽  
Vol 78 (2) ◽  
pp. 167-183 ◽  
Author(s):  
Clifford C Leznoff
Keyword(s):  
Organic Synthesis ◽  
Solid Phase ◽  
Diels Alder ◽  
Phase Method ◽  
Organic Chemical ◽  
Insect Pheromones ◽  
Polymer Supports ◽  
Solid Phase Organic Synthesis ◽  
Solid Phase Method ◽  
Solid Phases

Early developments in solid phase organic synthesis are traced. Particular emphasis is placed on the use of cross-linked polystyrene in the first general method of monoblocking symmetrical difunctional compounds. The monoprotected polymer-bound symmetrical starting materials were then used in multi-step syntheses of a variety of compounds, particularly insect pheromones. Asymmetric synthesis on polymer supports was demonstrated. Diels-Alder and 1,3-dipolar additions on polymer supports proceeded readily as did macrocyclic formation of porphyrins and phthalocyanines. All of these reactions clearly showed that most organic chemical reactions could be performed on solid phases and laid the basis for the development of combinatorial chemistry. The first unsymmetrical phthalocyanine was prepared using the solid phase method and this led eventually to solution phase methods of preparing bi-, tri-, tetra-, and even a dendritic-like pentanuclear phthalocyanine.Key Words: solid phase organic synthesis (SPOS), phthalocyanines.

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