Synthesis of 4-deoxydaunosamine and 4-deoxyristosamine

1980 ◽  
Vol 58 (16) ◽  
pp. 1751-1758 ◽  
Author(s):  
Hans H. Baer ◽  
Hanna R. Hanna
Keyword(s):  
Acetic Acid ◽  
Acid Hydrolysis ◽  
Sodium Borohydride ◽  
Catalytic Hydrogenation ◽  
Sodium Acetate ◽  
Amino Glycoside ◽  
Hydrolysis Of

Treatment of methyl 3,6-dideoxy-2,4-di-O-methylsulfonyl-3-nitro-α-L-glucopyranoside (2) with sodium acetate and acetic acid in acetone gave methyl 4-O-acetyl-2,3,6-trideoxy-3-nitro-α-L-erythro-hex-2-enopyranoside (3) as a kinetic product, and the 2-O-acetyl-3,4,6-trideoxy-3-nitro-α-L-threo-hex-3-eno isomer 4 as the thermodynamically preferred product. Treatment of 2 or 4 with sodium borohydride produced a separable mixture of methyl 2,3,4,6-tetradeoxy-3-nitro-α-L-threo-hexopyranoside (5) and its α-L-erythro epimer (6), the latter being convertible into the former by base-catalyzed epimerization. Acid hydrolysis of 5 and 6 afforded the corresponding free nitro sugars 7 and 8. Catalytic hydrogenation of 5 led to the corresponding amino glycoside, isolated as the acetate 9 or hydrochloride 10; similarly, 6 gave the epimeric amine which was isolated as its acetate 14 or picrate 15. N-Trifluoroacetylation of 9 provided the N-trifluoroacetyl glycoside 12 which was hydrolyzed to give a 49% yield (overall from 2) of 2,3,4,6-tetradeoxy-3-trifluoroacetamido-L-threo-hexose (4-deoxy-N-trifluoroacetyldaunosamine, 13). Analogously, 14 afforded the epimeric N-trifluoroacetyl glycoside 17 which was hydrolyzed to give a 28% overall yield of 2,3,4,6-tetradeoxy-3-trifluoroacetamido-L-erythro-hexose (4-deoxy-N-trifluoroacetylristosamine, 18).

A Stereospecific Synthesis of L-Desosamine

1974 ◽  
Vol 52 (1) ◽  
pp. 122-124 ◽  
Author(s):  
Hans H. Baer ◽  
Chung-Wai Chiu
Keyword(s):  
Acid Hydrolysis ◽  
Nitro Group ◽  
Catalytic Hydrogenation ◽  
Glycosidic Bond ◽  
Stereospecific Synthesis ◽  
Borohydride Reduction ◽  
Amino Glycoside ◽  
Hydrolysis Of

L-Desosamine (3,4,6-trideoxy-3-dimethylamino-L-xylo-hexose), the enantiomer of a widely distributed antibiotics component, was synthesized by borohydride reduction of methyl 3,4,6-trideoxy-3-nitro-α-L-erythro-hex-3-enopyranoside followed by catalytic hydrogenation of the nitro group, N,N-dimethylation of the resulting saturated amino glycoside, and acid hydrolysis of the glycosidic bond.

Preparation of enantiomeric and racemic 2,3,4,5-tetrahydroxypentyl derivatives of adenine, cytosine and uracil

1982 ◽  
Vol 47 (10) ◽  
pp. 2786-2805 ◽  
Author(s):  
Antonín Holý
Keyword(s):  
Acid Hydrolysis ◽  
Sodium Borohydride ◽  
Catalytic Hydrogenation ◽  
Protecting Groups ◽  
Sodium Salts ◽  
Hydrolysis Of ◽  
Derivatives Of ◽  
Subsequent Acid

1-(Adenin-9-yl)-1-deoxy-DL-ribitol (III), -D-arabitol (IXa), -L-arabitol (XIVa), -DL-xylitol (XXIVa), 1-(cytosin-L-yl)-1-deoxy-D-arabitol (IXb), -L-arabitol (XIVb), 1-(uracil-1-yl)-1-deoxy-D-arabitol (IXc), -L-arabitol (XIVc) and -DL-xylitol (XXIVb) were prepared by reaction of 1-O-p-toluenesulfonyl-2,3:4,5-di-O-isopropylidenealditols Ib, VIIb, XIIb and XXIIb with sodium salts of adenine, N4-benzoylcytosine or 4-methoxy-2-pyrimidone followed by removal of the protecting groups. Condensation of the mentioned sodium salts with methyl 5-O-p-toluenesulfonyl-2,3-O-isopropylidene-β-D-ribofuranoside (IV) with subsequent acid hydrolysis and reduction with sodium borohydride afforded 1-(adenin-9-yl)-1-deoxy-L-ribitol (VIa) and 1-(cytosin-1-yl)-1-deoxy-L-ribitol (VIb). 1-(Adenin-9-yl)-1-deoxy-L-lyxitol (XVII), -L-lyxitol (XVIII) and -2-O-methyl-D-lyxitol (XXI) were prepared analogously. Acid hydrolysis of 5-(adenin-9-yl)-5-deoxy-4-O-benzyl-1,2-O-isopropylidene-α-D-xylofuranose (XXVa), followed by reduction with sodium borohydride and catalytic hydrogenation, gave 1-(adenin-9-yl)-1-deoxy-L-xylitol (XXVIb).

The synthesis of D-angolosamine

1977 ◽  
Vol 55 (6) ◽  
pp. 1100-1103 ◽  
Author(s):  
Hans H. Baer ◽  
Fawzy F. Z. Georges
Keyword(s):  
Sodium Borohydride ◽  
Catalytic Hydrogenation ◽  
Title Compound ◽  
Amino Glycoside ◽  
Starting Point ◽  
Simplified Procedure

The synthesis of 2,3,6-trideoxy-3-dimethylamino-D-arabino-hexose hydrochloride (10) (D-angolosamine, a constituent of the antibiotic, angolamycin) is described. First, a simplified procedure for the preparation of methyl 6-deoxy-α-D-glucopyranoside from methyl α-D-glucopyranoside is recorded. The deoxy derivative served as the starting point for sequential preparation of methyl 3,6-dideoxy-3-nitro-α-D-glucopyranoside (1), its 2,4-diacetate (2), its 4-monoacetate (3), its 2-O-mesyl-4-acetate (4), its 2-mesylate (5), and methyl 2,3,6-trideoxy-3-nitro-α-D-erythro-hex-2-enopyranoside (6) essentially according to procedures previously established (in part, in the L-series). Treatment of 5 or 6 with sodium borohydride produced methyl 2,3,6-trideoxy-3-nitro-α-D-arabino-hexopyranoside (7). Catalytic hydrogenation of 7 gave the corresponding 3-amino glycoside hydrochloride (8) which was hydrolyzed to furnish 3-amino-2,3,6-trideoxy-D-arabino-hexose hydrochloride (9) (D-acosamine, the enantiomer of a component of the antibiotic, actinoidin). N,N-Dimethylation of 8 followed by hydrolysis afforded the crystalline title compound (10).

THE PREPARATION OF 9-HYDROXYPYRAZOLO[3,4-b]QUINOLINES

1966 ◽  
Vol 44 (17) ◽  
pp. 2009-2014 ◽  
Author(s):  
R. T. Coutts ◽  
J. B. Edwards
Keyword(s):  
Acetic Acid ◽  
Acetic Anhydride ◽  
Hydrazine Hydrate ◽  
Sodium Borohydride ◽  
Sodium Acetate ◽  
The Other ◽  
Reduction Product ◽  
Type I

4-(2-Nitrobenzylidene)-2-pyrazolin-5-ones (I) were best prepared by heating o-nitrobenzaldehyde and 2-pyrazolin-5-ones in acetic anhydride containing fused sodium acetate (cf. Erlenmeyer azlactone synthesis). Pyrazolones of type I were reductively cyclized with cyclohexene and palladium–charcoal, and gave 3a,4,9,9a-tetrahydro-9-hydroxy-1H-pyrazolo-[3,4-b]quinolines (II) which, as expected, were amphoteric compounds. Of the three other methods of reduction used in this study, two (zinc and acetic acid; sodium borohydride and palladium–charcoal) were capable of producing pyrazoloquinolines, but were less reliable. The other method employed (hydrazine hydrate and palladium–charcoal) caused degradation of the pyrazolone molecule in the two cases examined, and in both, bis(2-aminobenzylidene) hydrazine (V) was the reduction product isolated.

BIOSYNTHESIS OF NICOTINIC ACID BY FUSARIUM OXYSPORUM SCHLECHT

1967 ◽  
Vol 45 (12) ◽  
pp. 1953-1959 ◽  
Author(s):  
D. Desaty ◽  
L. C. Vining
Keyword(s):  
Nicotinic Acid ◽  
Fusarium Oxysporum ◽  
Acid Hydrolysis ◽  
Growth Phase ◽  
Sodium Acetate ◽  
Fusaric Acid ◽  
Early Growth ◽  
Pyridine Derivatives ◽  
Early Growth Phase ◽  
Hydrolysis Of

When the fungus Fusarium oxysporum was cultured on a glucose–nitrate–salts medium, synthesis of nicotinic acid occurred only during the early growth phase and preceded the accumulation of fusaric acid. Radioactivity from DL-tryptophan-benzene ring-14C was efficiently incorporated into nicotinic acid obtained by acid hydrolysis of the mycelium, whereas DL-tryptophan-β-14C, L-aspartate-U-14C, and sodium acetate-2-14C were poor precursors. Under the conditions of these experiments, all four substrates were poor precursors of fusaric acid. It is concluded that different pathways are used in the biosynthesis of these two pyridine derivatives, the route to nicotinic acid probably involving metabolism of tryptophan via the reactions known to occur in Neurospora crassa.

Pigments of Fungi. XXI. Synthesis of (±)-6-Demethoxyaustrocortirubin

1991 ◽  
Vol 44 (10) ◽  
pp. 1427 ◽  
Author(s):  
CJ Burns ◽  
M Gill ◽  
S Saubern
Keyword(s):  
Acetic Acid ◽  
Sodium Acetate ◽  
Benzylic Hydroxylation ◽  
High Yields ◽  
Hydrolysis Of

6-Demethoxyaustrocortirubin (6) is synthesized via the epoxide (21) which is available in 73% yield over four steps from naphthazarin (10). Hydrolysis of the epoxide (21) yields the diol (25) which on hydrogenolysis affords 6-demethoxy-1-deoxyaustrocortirubin (7). Stereoselective benzylic hydroxylation of (7) gives (6). Cleavage of the epoxide (21) with sodium acetate in acetic acid affords a mixture of the esters (22)-(24), while methanolysis yields the isomeric ethers (29) and (30). Hydrogenolysis of (22), (23) and (29) gives high yields of (7). Potentially more direct routes to the alcohol (7) involving oxymercuration, epoxidation and bromohydrin formation from the alkene (8) are not viable.

Stereospecific synthesis of isomeric 4-substituted 9-(2,3-dihydroxybutyl)adenines

1982 ◽  
Vol 47 (1) ◽  
pp. 173-189 ◽  
Author(s):  
Antonín Holý
Keyword(s):  
Acid Hydrolysis ◽  
Sodium Borohydride ◽  
Sodium Salt ◽  
Catalytic Hydrogenation ◽  
Sodium Azide ◽  
Sodium Iodide ◽  
Stereospecific Synthesis ◽  
Isopropylidene Derivative

Reduction of ethyl 2,3-O-isopropylidene-D-tartrate with sodium borohydride afforded (4S, 5S)-2,2-dimethyl-1,3-dioxolane-4,5-dimethanol (Va) which was benzoylated to give monobenzoyl derivative Vd and further transformed into p-toluensulfonyl derivative Ve. Reaction of the compound Ve with sodium salt of adenine followed by methanolysis gave 2,3-O-isopropylidene derivative Vf which on acid hydrolysis afforded 9-(2S, 3S)-(2,3,4-trihydroxybutyl)adenine (Ia). The enantiomer IIa was obtained from 3,4-O-isopropylidene-D-mannitol via (4R, 5R)-2,2-dimethyl-1,3-dioxolane-4,5-dimethanol (VIa) using the same procedure. Reaction of compounds Vf and VIf with p-toluenesulfonyl chloride afforded 4-O-p-toluenesulfonyl derivatives Vg and VIg. These compounds were also obtained from Va and VIa via di-p-toluenesulfonyl derivatives Vc and VIc by reaction with sodium salt of adenine. Treatment of compounds Vg and VIg with sodium iodide gave 4-iodo derivatives Vh and VIh which on reaction with tri-n-butyltin hydride, followed by acid hydrolysis, afforded enantiomeric threo-2,3-dihydroxybutyl derivatives Ib andIIb. Compounds Vg and VIg on treatment with sodium azide, subsequent catalytic hydrogenation of the intermediates Vj and VIj and acid hydrolysis afforded enantiomeric threo-9-(4-amino-2,3-dihydroxybutyl)adenines (Ic,IIc).

Cyclitols. XXXII. Cyclopentanepentols

1970 ◽  
Vol 23 (9) ◽  
pp. 1831 ◽  
Author(s):  
SJ Angyal ◽  
BM Luttrell
Keyword(s):  
Acetic Acid ◽  
Acid Hydrolysis ◽  
Strong Acid ◽  
Equilibrium Mixture ◽  
Relative Stabilities ◽  
Hydrolysis Of

Three cyclopentanepentols have been synthesized: the 1,2,4/3,5-isomer by acid hydrolysis of an anhydro-cyclopentanepentol, DL-1,2-anhydro-4,5-O-cyclohexylidene-1,2,3/4,5-cyclopentanepentol; the 1,2,3/4,5-isomer by deamination of (1,4/2,3,5)-5-amino-1,3-di-O-acetyl-2,3-O-cyclohexylidene-l,2,3,4-cycopentanetetrol; and the 1,2,3,4/5-isomer by solvolysis of two tetra-O-acetyl-O-tosylcyclopentanepentols. An equilibrium mixture of the three cyclopentanepentols was obtained by heating one of them with 95% acetic acid in the presence of a strong acid. The relative stabilities of the three isomers are in the order 1,2,4/3,5 > 1,2,3/4,5 > 1,2,3,4/5.

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