Nucleic acid components and their analogues. CXXIII. Synthesis of homouridine and homocytidine

Action du cyanure mercurique sur quelques halogénures de désoxy‐3‐trifluoroacétamido‐3‐D‐ribofurannosyle. Note de laboratoire

“…Nos rksultats montrent que, dans des conditions devant a priori favoriser la formation d'un cyanure de glycosyle, l'orientation depend aussi du substituant R du groupement acyle OCOR en C(2). Or, d'apres les travaux en skrie furannique [3] [ S ] [7-91, les …”

“…En traitant 4 (1,5 g, 2,7 mmol) dans de I'aice ac6tique (43 ml) par de I'anhydride acetique (3 ml, 32 mmol) en presence d'acide sulfurique concentre (0,9 ml) comme decrit pour la preparation de 5, on obtient 1 g (63%) de 7 cristallin: Rf 0,68 (AcOEtIhexane 1 : 1); F. 203, 2-207,5'; [a];' = + 57,1° (c = 0,5,CHCI,) = 5, J,,,,, = 12, 1H, H,-C(5)); 4.78 ( d x d , J4.5,= 3,3,1H,); 4,89 ( m , J 3 , 4 = 9 , lH, H-C(4)); 5,12 ( d x d , 246(13),209(29), 193 (25), 151 (49), 150(100), 139 (13) (2)); 6,40 (S, IH, H-C(1)); 8.37 (s, 8H, 2Ph). -S M .…”

“…Une solution de 5 (530 mg, 1,2 mmol) dans CH,CI, anhydre (16 ml 7,[2][3][4][5][6][7]6 et 7,l (2 m,3 et 2H,Ph). -SM.…”

Synthesis of substituted 2-(β-d-glucopyranosyl)-benzimidazoles and their evaluation as inhibitors of glycogen phosphorylase

“…Furanosyl benzimidazoles were prepared (a) by acid catalysed condensation of C-glycofuranosyl formic acids and o-phenylenediamine (OPD), 31,32 (b) by coupling of C-glycofuranosyl formic acids or their chlorides with 90 1,2-diaminobenzenes, followed by acid or POCl 3 mediated ring closure of the resulting amide type intermediates, 33,34 (c) in the reaction of C-glycofuranosyl formaldoximoyl chlorides (actually the nitrile oxide obtained by base induced dehydrochlorination) with OPD, 35 (d) by intramolecular ring closure of suitably protected 2-(pentitol-1 0 -yl)-benzimidazoles obtained from 2-lithiated benzimidazoles and sugar lactone or acyclic pentose derivatives, [36][37][38] and (e) by acid induced cyclodehydration of unprotected 2-(tetritol-1 0 -yl)-benzimidazoles.…”

Oxidation products of arachidonic acid. IV. Model studies on the attachaient of the C(13)—C(20) side-chain in the synthesis of tetrahydrofurans and pyrans 1,2, and 3

“…Hydrolysis of 5 with hydrochloric acid, followed by acetylation with p-nitrobenzoyl chloride in pyridine (5) gave 7 as a mixture of anomers. Treatment with hydrogen bromide in benzene at 0°C (6) transformed 7 to bromides 8, which, when submitted to the action of mercuric cyanide in nitromethane (6), gave the Pcyanide 9 as one isomer only, as established by nmr which showed the C(l) hydrogen as a broad singlet (J,,, 2 0-1) indicating a HI,,-dihedral angle of approximately 90°C. Alkaline hydrolysis gave the cyano alcohol 10, which was reduced with Raney nickel in the presence of diphenylethylene diamine (7,8) to the imidazoline 11.…”