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.

Hormone control in regeneration: effects of somatostatin on appendage regeneration, blood glucose and liver glycogen in Diemictylus viridescens

Development ◽  
1977 ◽  
Vol 40 (1) ◽  
pp. 115-124
Author(s):  
S. Vethamany-Globus ◽  
M. Globus ◽  
J. A. Hartford ◽  
I. Fraser ◽  
D. Weber
Keyword(s):  
Blood Glucose ◽  
Liver Glycogen ◽  
Inhibitory Effect ◽  
Thyroid Stimulating Hormone ◽  
Present Communication ◽  
Tail Regeneration ◽  
Experimental Animals ◽  
Total Inhibition ◽  
Daily Dose ◽  
Hormone Control

In the present communication, synthetic somatostatin, a hypothalamic factor which has a known inhibitory effect on the release of growth hormone, thyroid-stimulating hormone, prolactin, insulin and glucagon in man and other mammals, was found to have an inhibitory effect on limb and tail regeneration in adult Diemictylus viridescens, when the newts were treated with a daily dose of 3·5 or 15 µg/animal for a period of 34 days post-amputation. At the higher dose, the animals exhibited total inhibition of appendage regeneration in a few cases and the remainder showed a considerable delay compared to the controls; none of the experimental animals reached the advanced four-digit stage achieved by the controls. Furthermore, the blood glucose and liver glycogen values in the somatostatin-treated animals were significantly lower than the control values. Mechanisms in the storage, mobilization and utilization of glucose (involving hormones) are discussed in relation to appendage regeneration in the newt and possible controls of regeneration at the level of the hypothalamus are suggested.

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 and Biological Activity of New 16,17-Secoestrone Derivatives

2000 ◽  
Vol 65 (1) ◽  
pp. 77-82 ◽  
Author(s):  
Suzana Jovanović-Šanta ◽  
Silvana Andrić ◽  
Radmila Kovačević ◽  
Vjera Pejanović
Keyword(s):  
Biological Activity ◽  
Hydroxy Group ◽  
Sodium Borohydride ◽  
Estrogenic Activity ◽  
Complete Loss ◽  
Borohydride Reduction ◽  
Experimental Animals ◽  
Biological Tests ◽  
Sodium Borohydride Reduction

Starting from estrone 3-benzyloxy-17β-hydroxyestra-1,3,5(10)-trien-16-one oxime (3b) was synthesized, which underwent Beckmann fragmentation giving the 3-benzyloxy-17-oxo- 16,17-secoestra-1,3,5(10)-triene-16-nitrile (4b). Sodium borohydride reduction of this compound afforded 3-benzyloxy-17-hydroxy-16,17-secoestra-1,3,5(10)-triene-16-nitrile (5b). The deprotection of the 3-hydroxy group was achieved by action of hydrogen upon derivatives 4b and 5b in presence of Pd/C as a catalyst, yielding 3-hydroxy-17-oxo-16,17-secoestra- 1,3,5(10)-triene-16-nitrile (4a) and 3,17-dihydroxy-16,17-secoestra-1,3,5(10)-triene-16-nitrile (5a). In biological tests on experimental animals, compounds 4a, 4b, 5a and 5b showed virtually a complete loss of estrogenic activity, whereas compounds 4a, 5a and 5b exhibited moderate antiestrogenic effect.

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.

Ag Nanoparticles Decorated N-Doped Carbon Black as a High-Performance Catalyst for Catalytic Hydrogenation of p-Nitrophenol

NANO ◽  
2019 ◽  
Vol 14 (08) ◽  
pp. 1950095
Author(s):  
Jing Chen ◽  
Yanting Gao ◽  
Yongsheng Fu ◽  
Shugang Pan
Keyword(s):  
Catalytic Activity ◽  
Carbon Black ◽  
Synergistic Effect ◽  
Sodium Borohydride ◽  
Catalytic Hydrogenation ◽  
Ag Nanoparticles ◽  
High Performance ◽  
Significant Enhancement ◽  
Straightforward Method ◽  
High Dispersity

Ag nanoparticles decorated N-doped carbon black with different Ag content was synthesized via a straightforward method. The catalysts have been conducted in the catalytic hydrogenation of nitrophenols in the presence of sodium borohydride. The results show that Ag4/NCB possesses the highest catalytic activity for the catalytic hydrogenation of [Formula: see text]-nitrophenol ([Formula: see text]-NP) to [Formula: see text]-aminophenol ([Formula: see text]-AP). The significant enhancement in catalytic activity can be attributed to the high dispersity and smaller size of Ag nanoparticles, and remarkable synergistic effect of the combination of Ag nanoparticles and N-doped carbon black.

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).

Catalytic hydrogenation of nitrophenols and nitrotoluenes over a palladium/graphene nanocomposite

2014 ◽  
Vol 4 (6) ◽  
pp. 1742-1748 ◽  
Author(s):  
Jingwen Sun ◽  
Yongsheng Fu ◽  
Guangyu He ◽  
Xiaoqiang Sun ◽  
Xin Wang
Keyword(s):  
Sodium Borohydride ◽  
Catalytic Hydrogenation ◽  
Plausible Mechanism ◽  
Graphene Nanocomposite

A plausible mechanism for the reduction of p-nitrophenol catalyzed by a Pd/G catalyst in the presence of sodium borohydride.

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