Annie Grouiller

Réactions inhabituelles dans la synthèse et la substituition d'un triflate osdique

Abstract Triflation of methyl 3-azido-3,4-dideoxy-α or β-DL- threo -pentopyranoside with triethylamine as acid acceptor in dichloromethane, gave the two isomers of a 1:2′ , 2:1′ dianhydride. Benzoate displacement of the α triflate occured with a pyranose to furanose contraction reaction at C-2.

A novel stereospecific synthesis of 5-amino-1-β-D-fructofuranosylimidazole-4-carboxamide

A β-D-fructofuranose fused oxazolidine-2-thione has been isolated as the t-butyldimethylsilyl derivative (6), which when desulphurised and treated with α-amino-α-cyanoacetamide gave the silylated 1-β-D-fructofuranosyl aminoimidazole (2b) which when deblocked with methanolic hydrogen chloride produced 5-amino-β-D-fructofuranosyl-imidazole-4-carboxamide (2a).

Synthesis of Amino-Dideoxy-Dl-Pentopyranoses and Their Ureido Derivatives

Abstract Various 4-deoxy-α or β-erythro or threo-pentopyranoses aminated on position 1 [6 and 19]. 2 [38] or 3 [9, 22, 23, 24, 32 and 35] were synthesised from 2-methoxy-5,6-dihydro-2H-pyran [1] and methyl 2,3-anhydro-4-deoxy-α and β-DL-erythro-pentopyranoside [11]. Different reactions were investigated including azidation. cis-oxyamination, epimine formation and oxirane aminolysis. All these amino sugars were converted into their chloroethylureido derivatives.

Synthetic approaches to 6-substituted 9-(3-azido-3,4-dideoxy-β-d,l-erythro-pentopyranosyl)purines

Abstract Methyl 3-azido-2- O -benzoyl-3,4-dideoxy-β- dl - erythro -pentopyranoside ( 6 ) was synthesized through two routes in five steps from methyl 2,3-anhydro-4-deoxy-β- dl - erythro -pentopyranoside ( 1 ). The first route proceeded via selective azide displacement of the 3-tosyloxy group of methyl 4-deoxy-2,3-di- O -tosyl-α- dl - threo -pentopyranoside, followed by detosylation and benzoylation. The second route consisted, with a better overall yield, in the azide displacement of the mesyloxy group of methyl O -benzoyl-4-deoxy-3- O -methylsulfonyl-α- dl - threo -pentopyranoside ( 10 ), obtained by benzylate opening of 1 , followed by benzoylation, debenzylation, and mesylation. Compound 6 was transformed into its glycosyl chloride, further treated by 6-chloropurine to give the nucleoside 9-(3-azido-2- O -benzoyl-3,4-dideoxy-β- dl - erythro -pentopyranosyl)-6-chloropurine ( 13 ). When treated with propanolic ammonia, 13 yielded 9-(3-azido-3,4-dideoxy-β- dl - erythro -pentopyranosyl)adenine.

Some Aspects of Ribonucleoside Chemistry

Abstract New routes to the preparations of 2′-deoxy-3′-C-methyl uridine (2c) and 1-(5′-0-trityl-3′-deoxy-β-D-glycero-pentofuran-2-ulosyl)uracil (4) from 5′-0-trityl-2′-0-tosyl uridine (1) and 5′-0-trityl-3′-0-tosyl uridine (3) respectively are described.

Amination of Ethyl 5-Amino-1-Qlycofuranosylimidazole-4-Carboxylates Using Trimethylaluminium

Abstract Ethyl 5-amino-1-8-D-ribofuranosyl- and arabinofuranosyl imidazole-4-carboxylates were aminated by ammonia, primary and secondary amines to their corresponding 4-carboxamides using trimethylaluminium.

Synthesis of 6-Substituted Purine 2′-Azido- and 3′-Azido-Deoxypentopyranoses

Abstract Various 6-substituted purine 3′-(2′-) azido-3′, 4′-(2′, 4′-) dideoxy-β-DL-erythro-pentopyranoses (1) (2) have been prepared and compared in terms of a substituent electronegativity parameter. The nucleoside 1a (R=NH2) is a good competitive inhibitor of adenosine deaminase.

Contraction de cycle dans la substitution d'un triflate osidique

Benzoate displacement of the 2-triflyl derivative of methyl 3-azido or 3-O-benzoyl-4-deoxy-α-DL-thero-pentopyranoside (1 or 4) occurs with a pyranose to furanose contraction reaction at C-2. This contraction is not observed with an azido displacement.