Oligonucleotide Syntheses on Insoluble Polymer Supports. I. Stepwise Synthesis of Trithymidine Diphosphate

1967 ◽  
Vol 89 (2) ◽  
pp. 450-453 ◽  
Author(s):  
L. Russell. Melby ◽  
Donald R. Strobach
Keyword(s):  
Stepwise Synthesis ◽  
Polymer Supports ◽  
Insoluble Polymer

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.

scholarly journals The use of insoluble polymer supports as monoblocking groups of symmetrical diacid chlorides

1977 ◽  
Vol 18 (22) ◽  
pp. 1875-1878 ◽  
Author(s):  
Clifford C. Leznoff ◽  
Judah M. Goldwasser
Keyword(s):  
Polymer Supports ◽  
Insoluble Polymer

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.

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