Nucleic acid related compounds. 38. Smooth and high-yield iodination and chlorination at C-5 of uracil bases and p-toluyl-protected nucleosides

1982 ◽  
Vol 60 (5) ◽  
pp. 554-557 ◽  
Author(s):  
Morris J. Robins ◽  
Philip J. Barr ◽  
Jerzy Giziewicz
Keyword(s):  
Nucleic Acid ◽  
Organic Solvents ◽  
High Yield ◽  
Iodine Monochloride ◽  
High Yields ◽  
Related Compounds

Treatment of uracil bases and protected nucleosides with iodine monochloride (ICl) gave the corresponding 5-iodouracil products in over 95% purified yields. Analogously facile chlorination was effected with iodobenzene dichloride (PhICl2). Protection of the nucleosides as p-toluyl esters provided reactants that were soluble in organic solvents and crystallized readily in high yields.

Nucleic acid related compounds. 63. Synthesis of 5′-deoxy-5′-methyleneadenosine and related Wittig-extended nucleosides

1991 ◽  
Vol 69 (2) ◽  
pp. 334-338 ◽  
Author(s):  
Stanislaw F. Wnuk ◽  
Morris J. Robins
Keyword(s):  
Nucleic Acid ◽  
Key Words ◽  
Organic Bases ◽  
Key Words Adenosine ◽  
Tosyl Group ◽  
High Yields ◽  
Related Compounds

Treatment of the purified 5′-aldehyde (2a) (derived from 6-N-benzoyl-2′,3′-O-isopropylideneadenosine (1a)) with methylenetriphenylphosphorane and successive deprotection with ammonia and acid gave 9-(5,6-dideoxy-β-D-ribo-hex-5-enofuranosyl)adenine (5′-deoxy-5′-methyleneadenosine) (4). Oxidation of 1a or 2′,3′-O-isopropylideneadenosine (1b) and treatment of the crude 5′-aldehydes (2a or 2b) with (p-toluenesulfonylmethylene)triphenylphosphorane gave high yields of the 5′-deoxy-5′-tosylmethylene derivatives (5a or 5b). Removal of the tosyl group from 5b to give 3b was effected with tributylstannyllithium, but sulfone cleavage by the usual reductive methods failed. Reduction and deprotection of 5a or 5b gave 9-[5,6-dideoxy-6-(p-toluenesulfonyl)-β-D-ribo-hexofuranosyl]adenine (6b). Isomerization of the vinyl tosyl (5b) to a 4′,5′-unsaturated allylic tosyl derivative (7) occurred under cleavage conditions and in solutions of aqueous or organic bases. Key words: adenosine, 5′-deoxyadenosine, 5′-methylene-5′-deoxyadenosine, nucleosides.

Nucleic acid related compounds. 78. Stereocontrolled syntheses of 6′(E and Z)-halovinyl analogues from uridine-derived vinylsulfones via vinyltin intermediates

1993 ◽  
Vol 71 (2) ◽  
pp. 192-198 ◽  
Author(s):  
Stanislaw F. Wnuk ◽  
Morris J. Robins
Keyword(s):  
Nucleic Acid ◽  
Trifluoroacetic Acid ◽  
Bond Cleavage ◽  
Lead Tetraacetate ◽  
Acetylenic Derivative ◽  
Vinyl Derivative ◽  
High Yields ◽  
Related Compounds

Treatment of the 6′(E)-tosylvinyl homonucleoside 1a with Bu3SnH/AIBN/toluene/Δ gave separable mixtures of 6′-vinylstannanes 2a(E/Z) in high yields. Stereospecific halodestannylations with N-iodosuccinimide, bromine, and N-bromosuccinimide proceeded smoothly to give the 6′(E or Z)-iodo(and bromo) vinyl compounds with retention of configuration. Chlorine or iodobenzene dichloride effected moderately stereoselective chlorodestannylation. Treatment of 2a with NH4F/MeOH/Δ resulted in carbon–tin bond cleavage to give the free vinyl derivative 4a. Aqueous trifluoroacetic acid effected concomitant protiodestannylation and deprotection of 2a to give 4b. Treatment of 2a(E) with lead tetraacetate/acetonitrile and deprotection afforded acetylenic derivative 3b.

Nucleic acid related compounds. 67. Synthesis of 5′-amino and 5′-methylthio chain-extended nucleosides from uridine

1991 ◽  
Vol 69 (12) ◽  
pp. 2104-2111 ◽  
Author(s):  
Stanislaw F. Wnuk ◽  
N. Kent Dalley ◽  
Morris J. Robins
Keyword(s):  
Nucleic Acid ◽  
Sodium Borohydride ◽  
Conjugate Addition ◽  
Amino Derivative ◽  
Vinyl Sulfone ◽  
X Ray ◽  
Basic Solutions ◽  
High Yields ◽  
Wittig Reagent ◽  
Related Compounds

Treatment of 2′,3′-O-isopropylideneuridine-5′-aldehyde with the stabilized Wittig reagent, (p-toluenesulfonylmethylene)triphenylphosphorane, gave high yields of 1-[5,6-dideoxy-2,3-O-isopropylidene-6-(p-toluenesulfonyl)-β-D-ribo-hex-5(E)-enofuranosyl]uracil (2). This vinylsulfone (2) underwent isomerization readily in base to give the allylic sulfone, 1-[5,6-dideoxy-2,3-O-isopropylidene-6-(p-toluenesulfonyl)-β-D-erythro-hex-4(Z)-enofuranosyl]uracil (3). Treatment of 2 or 3 with aqueous trifluoroacetic acid gave the corresponding deprotected vinyl (5) or allylic (6) sulfones, and 5 was converted to 6 readily in basic solutions. Treatment of 2 with sodium borohydride, sodium thiomethoxide, or ammonia resulted in conjugate addition (at C5′ of the vinyl sulfone) to give the 5′-hydro, 5′-methylthio, or 5′-amino-5′,6′-dideoxy-6′-(p-toluenesulfonyl) nucleosides. The 5′-substituted diastereomers were deprotected, separated, and the configuration of a 5′-amino derivative was established by X-ray crystallography.Key words: allylic sulfones, amino-nucleosides, 5′,6′-dideoxynucleosides, nucleosides, uridine, vinyl sulfones.

Nucleic acid related compounds. 37. Convenient and high-yield syntheses of N-[(2-hydroxyethoxy)methyl] heterocycles as "acyclic nucleoside" analogues

1982 ◽  
Vol 60 (5) ◽  
pp. 547-553 ◽  
Author(s):  
Morris J. Robins ◽  
Peter W. Hatfield
Keyword(s):  
Nucleic Acid ◽  
Methyl Bromide ◽  
Antiviral Agent ◽  
Nucleoside Analogues ◽  
High Yield ◽  
Purine Derivatives ◽  
Acetyl Bromide ◽  
Acyclic Nucleoside Analogues ◽  
Acyclic Nucleoside ◽  
Related Compounds

Treatment of 1,3-dioxolane with acetyl bromide gave (2-acetoxyethoxy)methyl bromide (2a) in 88% yield. A number of pyrimidines and three chloropurines were trimethylsilylated and coupled with 2a. The respective N-1 and N-9 alkylated products (obtained in 79–89% yields) were deacetylated to give N-[(2-hydroxyethoxy)methyl] heterocycles. The 6-amino or 6-chloro substituent of the 2-amino-6-substituted-purine derivatives was hydrolyzed smoothly with adenosine deaminase to give 9-[(2-hydroxyethoxy)methyl]guanine (acycloguanosine), the potent antiviral agent.

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