Anhydro Derivatives Research Articles

Synthesis of the 2′-,3′-Didehydro-2′-,3′-dideoxy and 2′-,3′-Dideoxy Derivatives of 6-Azauridine and a New Route to 2′-,3′-Didehydro-2′-,3′-dideoxy-5-chlorouridine

Abstract The 5′-O-(4,4′-dimethoxytrityl) and 5′-O-(tert-butyldimethylsilyl) derivatives of 2′-,3′-O-thiocarbonyl-6-azauridine and 2′,3′-O-thiocarbonyl-5-chlorouridine were synthesized from the parent nucleosides by reaction with 4, 4′-dimethoxytrityl chloride and tert-butyldimethylsilyl chloride, respectively, followed by treatment with 1,1′-thiocarbonyldiimidazole. Introduction of a 2′-,3′-double bond into the sugar ring by reaction of the 5′-protected 2′-,3′-O-thionocarbonates with 1, 3-dimethyl-2-phenyl-1, 3, 2-diazaphospholidiine was unsuccessful, but could be accomplished satisfactorily with trimethyl phosphite. Reactions were generally more successful with the 5′-silylated than with the 5′-tritylated nucleosides. Formation of 2′-,3′-O-thiocarbonyl derivatives proceeded in higher yield with 5′-protected 6-azauridines than with the corresponding 5-chlorouridines because of the propensity of the latter to form 2,2′-anhydro derivatives. In the reaction of 5′-O-(tert-butyldimethylsilyl)-2′-,3′-O-thiocarb...

6-O-Demethyl-5-deoxyfusarubin and its anhydro derivative produced by a mutant of the fungus Nectria haematococca blocked in fusarubin biosynthesis.

6-O-Demethyl-5-deoxyfursarubin and 6-O-demethyl-5-deoxyanhydrofusarubin have been isolated from the mutant redD169.yelY9 of the fungus Nectria haematococca blocked in fusarubin biosynthesis. These products were identified on the basis of physico-chemical data by comparison with known substances.

ChemInform Abstract: Nucleosides. Part 152. 2′‐Azido‐2′,3′‐dideoxy Pyrimidine Nucleosides. Synthesis and Antiviral Activity Against Human Immunodeficiency Virus.

AbstractThe benzoyluridines (I) are dehydrated by reaction with diphenyl carbonate to form the 2,2'‐anhydro derivatives (II).

ChemInform Abstract: One‐Step Conversion of Thymidine into 2,3′‐Anhydro Derivatives.

2,3′-Anhydro derivatives of thymidine are obtained in ca. 80% yield by a one-pot transformation involving a tandem Mitsunobu reaction.

ChemInform Abstract: Pseudo‐Sugars. Part 26. Synthesis of Some Anhydro Derivatives of DL‐1‐C‐Hydroxymethyl‐1,2,3,4,5,6‐cyclohexanehexol.

AbstractThe synthesis of the three stereoisomeric title compounds (VIII), (IX) and (XI) is described.

Synthesis of Some Anhydro Derivatives of Dl-1-C-Hydroxymethyl-1,2,3,4,5,6-cyclohexanehexol

Abstract Three stereoisomers of Dl-1-C-(hydroxymethyl) conduritol epoxides have been synthesized in order to investigate their inhibitory activity against certain glycosyl hydrolases.

Silyl migration and formation of an anhydro derivative on attempted benzylation of 3- O- tert-butyldimethylsilyl-6- O-tosyl- d-glucal

Synthese d'anhydro-3,6 O-t-butyldimethylsilyl-4 glucal a partir d'O-tosyl-6 glucal et de butyl chloro dimethyl silane

One-step conversion of thymidine into 2,3′-anhydro derivatives

2,3′-Anhydro derivatives of thymidine are obtained in ca. 80% yield by a one-pot transformation involving a tandem Mitsunobu reaction.

Synthesis of 3'-azido-2',3'-dideoxy-6-methyluridine, 2',3'-dideoxy-6-methyluridine and 2',3'-dideoxy-2',3'-didehydro-6-methyluridine

3'-Azido-2',3'-dideoxy-6-methyluridine (VIb) was prepared, together with its N3-isomer VIIb, by opening the 2,3'-bond in anhydronucleoside III with lithium azide in dimethylformamide and subsequent detritylation. The anhydro derivative III was synthesized from 2'-deoxy-6-methyluridine (I) by tritylation, mesylation and closure of the 2,3'-anhydro bond with 1,8-diazabicyclo[5.4.0]undec-7-ene. Dideoxy derivative XV was prepared by Barton deoxygenation of phenoxythiocarbonyl derivative IX followed by desilylation with tetrabutylammonium fluoride. Reduction of bis(phenoxythiocarbonyl) derivative XV with tributyltin hydride afforded 2',3'-dideoxy-2',3'-didehydro derivative XVI. The compound XV was obtained from arabinosyl derivative XIII which arises, along with 5,6-dihydro derivative XIV, by reaction of anhydronucleoside XII with lithium hydroxide in aqueous methanol. Desilylation of compound XVI with tetrabutylammonium fluoride resulted in quantitative removal of 6-methyluracil.

ChemInform Abstract: Cyclization of Dialkyl Dithioacetals of L‐Arabinose Through the 5‐Tosylates.

AbstractReaction of the arabinose dithioacetals (I) with tosyl chloride (II) and subsequent base‐induced cyclization yield a mixture of the new anhydro derivatives (IV) and (V).

Transformations of gossypol in low-molecular-mass alcohols

It has been shown that the transformations of gossypol into anhydro derivatives on its storage in methanol, ethanol, and propanol take place the faster the lower the molecular mass of the alcohol and the higher the temperature of the process. It has been established that when alcoholic solutions of gossypol in methanol are heated it is converted completely into dianhydrogossypol, in propanol into monoanhydrogossypol, and in ethanol into a mixture of equal amounts of mono- and dianhydro derivatives.

Synthesis and antiviral activity of several 2,5'-anhydro analogues of 3'-azido-3'-deoxythymidine, 3'-azido-2',3'-dideoxyuridine, 3'-azido-2',3'-dideoxy-5-halouridines, and 3'-deoxythymidine against human immunodeficiency virus and Rauscher-murine leukemia virus.

Several 2,5'-anhydro analogues of 3'-azido-3'-deoxythymidine (AZT), 3'-azido-2'3'-dideoxyuridine (AZU), 3'-azido-2'3'-dideoxy-5-bromouridine, 3'-azido-2',3'-dideoxy-5-iodouridine, and 3'-deoxythymidine and the 3'-azido derivative of 5-methyl-2'-deoxyisocytidine have been synthesized for evaluation as potential anti-HIV (human immunodeficiency virus) agents. These 2,5'-anhydro derivatives, compounds 13-17, demonstrated significant anti-HIV-1 activity with IC50 values of 0.56, 4.95, 26.5, 27.1, and 48 microM, respectively. Compared to that of the parent compounds AZT and AZU, the respective 2,5'-anhydro analogues, compounds 13 and 14, were somewhat less active. Whereas AZT was cytotoxic with a TCID50 of 29 microM, the toxicity of the 2,5'-anhydro derivative of AZT, compound 13, was reduced considerably to a TCID50 value of greater than 100 microM. The 2,5'-anhydro analogue of 5-methyl-2'-deoxyisocytidine also demonstrated anti-HIV-1 activity with an IC50 value of 12 microM. These compounds were also evaluated against Rauscher-Murine leukemia virus (R-MuLV) in cell culture. Among them, AZT, 3'-azido-2',3'-dideoxy-5-iodouridine, 3'-azido-2',3'-dideoxy-5-bromouridine, and 2,5'-anhydro-3'-azido-3'-deoxythymidine (13) were found to be most active, with IC50 values of 0.023, 0.21, 0.23, and 0.27 microM, respectively.

Behaviour of 2′-O-p-toluenesulfonyl uridine towards excess of a Grignard reagent

Two C-methylated base nucleosides were obtained when 2′-O-tosyl-5′-O-trityluridine was reacted with 30 equivalents of methylmagnesium iodide. Keywords: nucleoside, Grignard reaction, C-methyl pyrimidinone, anhydro derivative, arabinofuranosyl.

Reaction of 6-azauridine with thionyl chloride in hexamethylphosphoramide

Reaction of 6-azauridine (I) with a mixture of thionyl chloride and hexamethylphosphoramide afforded 5'-chloro-5'-deoxy-6-azauridine (II) and a mixture of SR- and SS-isomers of 5'-chloro-5'-deoxy-2',3'-O-sulfinyl-6-azauridine (IIIa and IIIb) which were separated by column chromatography on silica gel; compounds IIIa and IIIb also arose in the reaction of compound II with diphenyl sulfite. Removal of the cyclic sulfinyl group from the isomeric sulfites IIIa and IIIb gave compound II; reaction of IIIa and IIIb with imidazole in dimethylformamide afforded the 5'-chloro-5'-deoxy-2,2'-anhydro derivative IV.

ChemInform Abstract: Synthesis of 2‐(D‐allo‐ and D‐altro‐Pentitol‐1‐yl)pyridines and Their 2′,5′‐Anhydro Derivatives.

AbstractReaction of the silylpyridine (I) with the aldehydo‐D‐ribose (II) produces a mixture of the D‐allo‐ (IIIa) and D‐altro‐pentitolylpyridines (IIIb) respectively.

ChemInform Abstract: A Ready Route to a Functionalized Anhydro Derivative of 1,6‐Anhydro‐β‐D‐glucopyranose (Levoglucosan).

ChemInform Abstract: A Ready Route to a Functionalized Anhydro Derivative of 1,6‐Anhydro‐β‐D‐glucopyranose (Levoglucosan).

Studies on the Dehydration of New 2- (Pentitol-1-YL) Pyridines HavingD-Gulo,D-IDO, andL-MannoConfigurations

Abstract Fusion of 2-trimethylsilylpyridine and tetra-O-acetyl-aldehydo-D-xylose or 2,3:4,5-di-O-isopropylidene-aldehydo-L-arabinose led, after removing of the protecting groups, to 2-(pentitol-1-yl)pyridines of D-gulo and D-ido or L-manno configurations. Dehydration of the sugar-chain with D-gulo and D-ido configurations gave the corresponding 2′,5′-anhydro derivatives, whereas 2-(5-O-isopropyl-L-manno-pentitol-1-yl)-pyridine was the only compound formed by dehydration of the sugar-chain with L-manno configuration. Structural proofs are based on 1H and 13C NMR spectra.

Preparation and some reactions of bis(2',3'-O-carbonyl-6-azauridine) 5',5''-carbonate

Reaction of 6-azauridine (I) with phosgene and hexamethylphosphoramide afforded the title compound II. Both its 2',3'-cyclic carbonate groups were selectively deblocked with methanolic sodium methoxide under preservation of the internucleoside carbonate bridge. The carbonate II was also converted into the 5',5''-carbonyloxybis(2,2'-anhydro) derivative III by heating with imidazole in N,N-dimethylformamide. Several analogues of II were prepared by reaction of 1,1'-carbonyldiimidazole with the corresponding nucleosides in N,N- dimethylformamide.

Synthesis of 2-(d-allo- and d-altro-pentitol-1-yl)pyridines and their 2′,5′-anhydro derivatives

Synthesis of 2-(d-allo- and d-altro-pentitol-1-yl)pyridines and their 2′,5′-anhydro derivatives

A ready route to a functionalized anhydro derivative of 1,6-anhydro-β-D-glucopyranose (levoglucosan)

A ready route to a functionalized anhydro derivative of 1,6-anhydro-β-D-glucopyranose (levoglucosan)