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).

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).

The synthesis of model lactones of cyclolignan type

1981 ◽  
Vol 46 (9) ◽  
pp. 2123-2128 ◽  
Author(s):  
Jiří Křepelka ◽  
Jiří Holubek
Keyword(s):  
Sodium Borohydride ◽  
Catalytic Hydrogenation ◽  
Dicarboxylic Acids ◽  
Inhibitory Effect ◽  
Experimental Animals

Lactones VI-IX were prepared on reduction of anhydrides of 4-aryl-1-methoxynaphthalene-2,3-dicarboxylic acids IV and V with sodium borohydride in methanol. Catalytic hydrogenation on platinum of lactones VIII and IX gave lactones with hydrogenated ring A, or A and C. Lactones XII and XIII were found to possess an inhibitory effect on the growth of the tumour S 37 in experimental animals.

A New Approach to 3′-Amino-3′-deoxynucleosides. Synthesis of 9-(3-Amino-3-deoxy-α-L-ribofuranosyl)adenine

1971 ◽  
Vol 49 (4) ◽  
pp. 568-573 ◽  
Author(s):  
Hans H. Baer ◽  
Monika Bayer
Keyword(s):  
Catalytic Hydrogenation ◽  
Title Compound ◽  
Condensation Product ◽  
Periodate Oxidation ◽  
Borohydride Reduction ◽  
New Approach

Methyl 2,3,4-tri-O-acetyl-6-deoxy-6-nitro-α-D-glucopyranoside (1) was acetolyzed to give 1,2,3,4-tetra-O-acetyl-6-deoxy-6-nitro-α-D-glucopyranose (2). Compound 2 (or alternatively, 6-deoxy-1,2-O-isopropylidene-6-nitro-α-D-glucofuranose 4) was converted into 2,3,4-tri-O-acetyl-6-deoxy-6-nitro-α- D-glucopyranosyl bromide (3) which was condensed with chloromercuri 6-benzamidopurine. De-O-acetylation of the condensation product 5 afforded 6-benzamido-9-(6-deoxy-6-nitro-β-D-glucopyranosyl)purine (6) which could be hydrogenated to the corresponding 6′-amino nucleoside 7. Periodate oxidation of 6 followed by internal Henry cyclization and borohydride reduction gave 6-benzamido-9-(3-deoxy-3-nitro-α-L-ribofuranosyl)purine (10) which upon catalytic hydrogenation and subsequent de-N-benzoylation produced the title compound, 12. The sensitivity of certain nitro intermediates towards alkali is commented upon.

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.

Model reactions for a synthesis of streptamine based on the diamination of nitrocyclitol acetates

1968 ◽  
Vol 46 (17) ◽  
pp. 2793-2797 ◽  
Author(s):  
Hans H. Baer ◽  
Margaret C. T. Wang
Keyword(s):  
Sodium Borohydride ◽  
Catalytic Hydrogenation ◽  
Borohydride Reduction ◽  
Permanganate Oxidation ◽  
Sodium Borohydride Reduction ◽  
Model Reactions

Treatment of trans,trans-2-nitro-1,3-cyclohexanediol diacetate with ammonia followed by acetylation gives trans,trans 1,3-diacetamido-2-nitrocyclohexane (4). Catalytic hydrogenation of 4 and subsequent acetylation lead to trans,trans-2,6-diacetamidocyclohexylamine (5) and trans,trans-1,2,3-triacetamidocyclohexane (6), respectively. Permanganate oxidation of 4 affords cis-2,6-diacetamidocyclohexanone (7; 2,4-dinitrophenylhydrazone, 8). Sodium borohydride reduction of 7 produces trans,trans-2,6-diacetamidocyclohexanol (9; O-acetate, 10).

Bromate reduction in water by catalytic hydrogenation using metal–organic frameworks and sodium borohydride

RSC Advances ◽  
2015 ◽  
Vol 5 (54) ◽  
pp. 43885-43896 ◽  
Author(s):  
Kun-Yi Andrew Lin ◽  
Shen-Yi Chen
Keyword(s):  
Sodium Borohydride ◽  
Catalytic Hydrogenation ◽  
Metal Organic Frameworks ◽  
Metal Organic ◽  
Bromate Reduction

Catalytic hydrogenation of bromate is a promising approach to remove bromate from water considering that this approach not only removes bromate but also converts it to bromide.

Potential noncataleptic neuroleptic agents: Synthesis and pharmacology of 7-chloro-4-[4-(2-hydroxyethyl)piperazino]-4,5-dihydrothieno[2,3-b]-1-benzothiepin

1983 ◽  
Vol 48 (10) ◽  
pp. 2970-2976 ◽  
Author(s):  
Zdeněk Polívka ◽  
Martin Valchář ◽  
Miroslav Protiva
Keyword(s):  
Sodium Borohydride ◽  
Potassium Carbonate ◽  
Title Compound ◽  
Potassium Hydroxide ◽  
Dopamine Metabolism ◽  
High Dose ◽  
Chloro Derivative ◽  
Hydroxyethyl Piperazine ◽  
Central Depressant ◽  
Boiling Toluene

Heating of 2,5-dichloroacetophenone with 2-thiophenethiol, potassium carbonate and copper gave 5-chloro-2-(2-thienylthio)acetophenone (V) which was subjected to the Willgerodt reaction with sulphur and morpholine. The product was a mixture of the thiomorpholide VI and oxothiomorpholide VII. After a partial separation the predominanting product VI was hydrolyzed without characterization with ethanolic potassium hydroxide to give the acid VIII. Cyclization by treatment with phosphorus pentoxide in boiling toluene gave 7-chlorothieno[2,3-b]-1-benzothiepin-4(5H)-one (X) which was reduced with sodium borohydride to the alcohol XII. A reaction with hydrogen chloride in benzene led to the chloro derivative XIII whose substitution reaction with 1-(2-hydroxyethyl)piperazine afforded the title compound IV. The product has strong central depressant and discoordinating activity, a low cataleptic efficity but in a relatively high dose it does not influence the dopamine metabolism in the rat brain.

SYNTHESIS OF 3-AMINO-2,3-DIDEOXY-D-lyxo-HEXOSE

1965 ◽  
Vol 43 (11) ◽  
pp. 3074-3079 ◽  
Author(s):  
Hans H. Baer ◽  
Frank Kienzle
Keyword(s):  
Aspartic Acid ◽  
Catalytic Hydrogenation ◽  
Title Compound ◽  
Amine Hydrochloride ◽  
Derivatives Of ◽  
Potential Use

Catalytic hydrogenation of methyl 4,6-O-benzylidene-2,3-dideoxy-3-nitro-β-D-threo-hexo-pyranos-2-enide (I) afforded methyl 4,6-O-benzylidene-2,3-dideoxy-3-nitro-β-D-lyxo-hexo-pyranoside (II). Acid debenzylidenation and further hydrogenation gave in turn methyl 2,3-dideoxy-3-nitro-β-D-lyxo-hexopyranoside (III) and the corresponding amine hydrochloride (IV). Several crystalline derivatives of IV were prepared, and the configuration at C-3 was proved by degradation of the N-benzoate (VII) to N-benzoyl-D-aspartic acid. The title compound (V) was obtained as a chromatographically homogeneous sirup.Some methyl 3-deoxy-3-nitro-β-L-hexopyranosides were prepared for potential use as starting materials in analogous syntheses in the L-series.

Sign in / Sign up

Export Citation Format

Share Document