scholarly journals The Use of Polymer Supports in Organic Synthesis. III. Selective Chemical Reactions on One Aldehyde Group of Symmetrical Dialdehydes

1973 ◽  
Vol 51 (22) ◽  
pp. 3756-3764 ◽  
Author(s):  
Clifford C. Leznoff ◽  
Jack Y. Wong
Keyword(s):  
Aldol Condensation ◽  
Aluminum Hydride ◽  
Aldehyde Group ◽  
Polymer Support ◽  
High Yield ◽  
Yield Reduction ◽  
Polymer Supports ◽  
Acid Cleavage ◽  
Unique Method ◽  
Insoluble Polymer

An insoluble polymer support system incorporating a diol functional group was prepared. The symmetrical dialdehydes, terephthalaldehyde and isophthalaldehyde, were attached to the polymer through acetal formation, constituting a unique method of blocking one aldehyde group of symmetrical dialdehydes. The free aldehyde group was reacted with hydroxylamine to give the mono-oximes of the terephthalaldehyde and isophthalaldehyde upon acid cleavage from the polymer. Similarly, the polymer bound aldehydes were reacted with Wittig reagents to give p- and m-formylstilbenes and 1-p- and -m-formyl-phenyl-4-phenyl-1,3-butadienes. The crossed aldol condensation of acetophenone with the symmetrical dialdehydes gave the 3-p- and -m-formylphenyl-1-phenyl-2-propene-1-ones (formylchalcones) in high yield. The Grignard reaction of phenylmagnesium bromide on the polymer bound aldehyde gave(p- and m-formylphenyl)phenylcarbinol in quantitative yield. Reduction of the polymer bound free aldehydes with sodium bis(2-methoxyethoxy)-aluminum hydride gave p- and m-hydroxymethylbenzaldehydes. Similarly the mixed benzoin condensation of polymer bound terephthalaldehyde and isophthalaldehyde gave p- and m-formylbenzils.

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 The monoblocking of symmetrical diketones on insoluble polymer supports

1983 ◽  
Vol 61 (7) ◽  
pp. 1405-1409 ◽  
Author(s):  
Zhang-Huang Xu ◽  
Colin R. McArthur ◽  
Clifford C. Leznoff
Keyword(s):  
Acid Hydrolysis ◽  
Nmr Spectra ◽  
High Yield ◽  
Styrene Copolymer ◽  
Polymer Supports ◽  
Vicinal Diol ◽  
Insoluble Polymer ◽  
C Nmr ◽  
Phenylmagnesium Bromide

A 1% crosslinked divinylbenzene–styrene copolymer, incorporating vicinal diol groups or their isopropylidenc precursors, was used to form the monoacetals of the symmetrical diketones, p-diacetylbenzene, 1,2-cyclohexanedione, 1,3-cyclohexanedionc, 1,4-cyclohexanedione, and 2,5-hexanedione. The free ketone groups reacted with phenylmagnesium bromide to give, in high yield, after acid hydrolysis from the polymer, the expected products such as 3-phenyl-2-cyclohexen-1-one from 1,3-cyclohexanedione. The 13C nmr spectra of some polymer-bound substrates and simple analogs are described.

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.

Synthesis of the San Jose scale's sex pheromone component using insoluble polymer support

1989 ◽  
Vol 10 (2-3) ◽  
pp. 315-316
Author(s):  
Zu Zhanghuang ◽  
Chen Jiawei ◽  
Jiang Jilong ◽  
Wang Shiming ◽  
Pan Yijun
Keyword(s):  
Sex Pheromone ◽  
Pheromone Component ◽  
Polymer Support ◽  
San Jose ◽  
Insoluble Polymer

Neuroanatomy

2013 ◽  
Author(s):  
Adam Fisch
Keyword(s):  
Learning Experience ◽  
High Yield ◽  
Brain Images ◽  
Advanced Level ◽  
Muscle Testing ◽  
Effective Manner ◽  
Hands On ◽  
Yield Learning ◽  
Unique Method ◽  
Learning Points

Neuroanatomy: Draw It to Know It, Second Edition teaches neuroanatomy in a purely kinaesthetic way. In using this resource, each neuroanatomical pathway and structure is learned by drawing, and through this process, memorable and reproducible schematics for the various learning points in neuroanatomy are created in a hands-on, enjoyable, and highly effective manner. In addition to this unique method, this resource also provides a remarkable repository of reference materials, including numerous anatomic and radiographic brain images, muscle-testing photographs, and illustrations from many other classic texts, which all enhance the learning experience. This new edition adds "Know-It" points to each chapter, providing high-yield learning methods that separate the essential from the advanced topics. It engages the reader in a direct manner while covering both the advanced level of detail needed as well as retaining the simplistic approach used in learning this challenging subject.

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