A Synthesis of 2-Amino-2,6-dideoxy-D-(and L-)galaetose (Fucosamine) and 2-Amino-2,6-dideoxy-D-(and L-)talose (Pneumosamine)

1973 ◽  
Vol 51 (6) ◽  
pp. 974-977 ◽  
Author(s):  
Malcolm B. Perry ◽  
Virginia Daoust
Keyword(s):  
Similar Reaction ◽  
Reaction Sequence ◽  
Reaction Conditions ◽  
Nef Reaction ◽  
Methanolic Ammonia

5-Deoxy-D-lyxose underwent base-catalyzed addition with nitromethane to give a mixture of 1,6-dideoxy-1-nitro-D-galactitol and 1,6-dideoxy-1-nitro-D-talitol (ca. 2:1). Acetylation of the crystalline 1,6-dideoxy-1-nitro-D-galactitol gave 2,3,4,5-tetra-O-acetyl-1,6-dideoxy-1-nitro-D-galactitol which on treatment with methanolic ammonia afforded 2-acetamido-1,2,6-trideoxy-1-nitro-D-talitol and 2-acetamido-1,2,6-trideoxy-1-nitro-D-galactitol (ca. 3:1) which under the modified Nef reaction conditions gave 2-acetamido-2,6-dideoxy-D-talose and 2-acetamido-2,6-dideoxy-D-galactose respectively. The glycoses were converted to 2-amino-2,6-dideoxy-D-talose hydrochloride and 2-amino-2,6-dideoxy-D-galactose hydrochloride on hydrolysis with hydrochloric acid.A similar reaction sequence applied to 5-deoxy-L-lyxose afforded the L-enantiomorphic intermediates, and gave 2-amino-2,6-dideoxy-L-talose hydrochloride and 2-amino-2,6-dideoxy-L-galactose hydrochloride as final products.

scholarly journals Appel-reagent-mediated transformation of glycosyl hemiacetal derivatives into thioglycosides and glycosyl thiols

2013 ◽  
Vol 9 ◽  
pp. 974-982 ◽  
Author(s):  
Tamashree Ghosh ◽  
Abhishek Santra ◽  
Anup Kumar Misra
Keyword(s):  
Reaction Sequence ◽  
Reaction Conditions ◽  
One Pot ◽  
Carbon Tetrabromide

A series of glycosyl hemiacetal derivatives have been transformed into thioglycosides and glycosyl thiols in a one-pot two-step reaction sequence mediated by Appel reagent (carbon tetrabromide and triphenylphosphine). 1,2-trans-Thioglycosides and β-glycosyl thiol derivatives were stereoselectively formed by the reaction of the in situ generated glycosyl bromides with thiols and sodium carbonotrithioate. The reaction conditions are reasonably simple and yields were very good.

Use of allylzinc halide as a source of halide: Differential addition of nucleophiles to Ts-aziridines and aldehydes under similar reaction conditions

2019 ◽  
Vol 60 (3) ◽  
pp. 276-283 ◽  
Author(s):  
Rana Chatterjee ◽  
Satyajit Samanta ◽  
Anindita Mukherjee ◽  
Sougata Santra ◽  
Grigory V. Zyryanov ◽  
...  
Keyword(s):  
Similar Reaction ◽  
Reaction Conditions

scholarly journals Silver(I) and Copper(I) Complexation with Decachloro-Closo-Decaborate Anion

Crystals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 389
Author(s):  
Varvara V. Avdeeva ◽  
Grigoriy A. Buzanov ◽  
Elena A. Malinina ◽  
Nikolay T. Kuznetsov ◽  
Anna V. Vologzhanina
Keyword(s):  
Complexation Reaction ◽  
Similar Reaction ◽  
Cluster Anions ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
Boron Cluster ◽  
Composition And Structure ◽  
Coinage Metals ◽  
Closo Decaborate Anion ◽  
Complexation Reactions

A series of complexation reactions of silver(I) and copper(I) in the presence of a polyhedral weakly coordinating [B10Cl10]2− anion has been carried out. The effect of the solvent and the presence of Ph3P on the composition and structure of the reaction product were studied. Eight novel complexes were obtained and characterized by 11B Nuclear magnetic resonance, Infra-Red, and Raman spectroscopies as well as powder and single-crystal X-ray diffraction techniques. The [B10Cl10]2− anion demonstrated weaker coordinating ability towards coinage metals than [B10H10]2− at similar reaction conditions. The [B10Cl10]2− anion remains unreacted in the copper(I) complexation reaction, while in the absence of competing ligands, we obtained the first complexes containing decachloro-closo-decaborate anion directly coordinated by the metal atom. The bonding between metal atoms and the boron cluster anions was studied using the atomic Hirshfeld surfaces. Besides edge and face coordination of the polyhedral anion, this method allowed us to reveal the Ag–Ag bond in crystal of {Ag2(DMF)2[B10Cl10]}n, the presence of which was additionally supported by the Raman spectroscopy data.

Synthesis of 3-(4′-Methoxyphenyl)-2,2,4,4-Tetramethylpentane and Some Cyclic Analogs

1986 ◽  
Vol 39 (12) ◽  
pp. 2095 ◽  
Author(s):  
DJ Collins ◽  
HA Jacobs
Keyword(s):  
Methanesulfonic Acid ◽  
Similar Reaction ◽  
Reaction Sequence ◽  
Quinone Methides ◽  
Hydride Reduction ◽  
Lithium Aluminium ◽  
Clemmensen Reduction ◽  
Analogous Manner ◽  
Hydrolysis Of ◽  
Zinc Iodide

Reaction of 1-methoxy-2-methyl-1-trimethylsilyloxyprop-1-ene (8) with 1-acetoxy-1-(4′-methoxyphenyl)-2,2-dimethylpropane (7b) in the presence of zinc iodide gave 84% of methyl 3-(4′methoxyphenyl)-2,2,4,4- tetramethylpentanoate (9a), which was reduced with lithium aluminium hydride to 3-(4′-methoxyphenyl)-2,2,4,4-tetramethylpentan-1-ol(12a). Hydride reduction of the derived tosylate (12b) afforded 3-(4′-methoxyphenyl )-2,2,4,4-tetramethylpentane (5b) which upon demethylation yielded the corresponding phenol (10a). In an analogous manner, 1-acetoxy-1-(4′-methoxyphenyl)-2-methylpropane (7d) was converted into 3- (4′-hydroxyphenyl)-2,2,4-trimethylpentane (10b). By a similar reaction sequence, 6-methoxy-2,2-dimethyl-3,4- dihydronaphthalen-1(2H)-one (14) was transformed into 6-hydroxy-2,2- dimethyl-1-(1′,1′-dimethylethyl)-1,2,3,4-tetrahydronaphthalene (16b). Hydrolysis of the ester (9a) and cyclization of the resulting carboxylic acid (19) by treatment with methanesulfonic acid at 20° for 18 h afforded 3-(1′, 1′-dimethylethyl)-6-methoxy-2,2-dimethyl-2,3-dihydro-1H-inden-1-one (20). Clemmensen reduction of this followed by demethylation yielded 1-(1′,1′-dimethylethyl)-2,2-dimethyl-2,3-dihydro-1H-inden-5-ol (21b). Attempts to oxidize the phenols (10a), (10b), (16b) and (21b) to the corresponding quinone methides by conventional methods failed.

Synthesis of 2-amino-2-deoxy-D-allose, 2-amino-2-deoxy-D-altrose, and 2-deoxy-D-ribo-hexose from 3,4,5,6-tetraacetoxy-D-ribo-1-nitro-1-hexene

1968 ◽  
Vol 46 (17) ◽  
pp. 2859-2862 ◽  
Author(s):  
M. B. Perry ◽  
Jana Furdová
Keyword(s):  
Nef Reaction ◽  
Methanolic Ammonia

3,4,5,6-Tetraacetoxy-D-ribo-1-nitro-1-hexene with methanolic ammonia afforded a mixture of 2-acetamido-1,2-dideoxy-1-nitro-D-allitol and 2-acetamido-1,2-dideoxy-1-nitro-D-altritol, which were converted via the Nef reaction to 2-acetamido-2-deoxy-D-allose and 2-acetamido-2-deoxy-D-altrose. 2-Amino-2-deoxy-D-allose hydrochloride and 2-amino-2-deoxy-D-altrose hydrochloride were obtained from the 2-acetamido-2-deoxy-glycoses.Reduction of 3,4,5,6-tetraacetoxy-D-ribo-1-nitro-1-hexene afforded 3,4,5,6-tetra-O-acetyl-1,2-dideoxy-1-nitro-D-ribo-hexitol which was converted via the Nef reaction to 2-deoxy-D-ribo-hexose.

The reaction of some indoles with selenium dioxide

1967 ◽  
Vol 20 (2) ◽  
pp. 359 ◽  
Author(s):  
JFK Wilshire
Keyword(s):  
Selenium Dioxide ◽  
Complex Mixtures ◽  
Similar Reaction ◽  
Reaction Conditions

The reaction of selenium dioxide with indole in benzene gives 3,3?- diindolyl selenide. In separate experiments but with similar reaction conditions, 2-methyl-indole gave complex mixtures from which either 3,3?-di(2-methylindolyl) diselenide or the corresponding triselenide was isolated in low yield. 1,2-Dimethylindole gave 3,3?-di(1,2- dimethylindolyl) triselenide, also in low yield.

Simple and large-scale synthesis of β-phase molybdenum carbides as highly stable catalysts for dry reforming of methane

2018 ◽  
Vol 5 (1) ◽  
pp. 90-99 ◽  
Author(s):  
Haifeng Gao ◽  
Zhiwei Yao ◽  
Yan Shi ◽  
Renren Jia ◽  
Feixue Liang ◽  
...  
Keyword(s):  
Large Scale ◽  
Dry Reforming ◽  
Dry Reforming Of Methane ◽  
Similar Reaction ◽  
Reaction Conditions ◽  
Β Phase ◽  
Molybdenum Carbides ◽  
Catalytic Stability ◽  
Large Scale Synthesis

The catalytic stability of monometallic β-Mo2C/CNTs was found to be superior to that of bimetallic Ni/β-Mo2C under similar reaction conditions.

An unusual tert-butylamine mediated conversion of 6-aryl-7-formyl-2,4,5,8-tetrahydro-1,3-dioxa-5-azocines to 1,2,3,6-tetrahydropyrimidine derivatives

1990 ◽  
Vol 55 (10) ◽  
pp. 2502-2509 ◽  
Author(s):  
Ladislav Štibrányi ◽  
Lubor Fišera ◽  
Rastislav Káčer ◽  
Vladimír Oremus ◽  
Martina Mihulová
Keyword(s):  
Membered Ring ◽  
Dipolar Cycloaddition ◽  
Reaction Sequence ◽  
Pyrimidine Derivatives ◽  
Reaction Conditions ◽  
Photochemical Rearrangement ◽  
Tert Butylamine

An unexpected contraction of the 8-membered ring to a 6-membered one occurring when 6-aryl-7-formyl-2,4,5,8-tetrahydro-1,3-dioxa-5-azocines II were treated with tert-butylamine afforded 4-aryl-5-formyl-1-(1,1-dimethylethyl)-1,2,3,6-tetrahydropyrimidines III. Reaction conditions for the photorearrangement of chlorophenyl-substituted condensed isoxazolines I to II were worked out. The reaction sequence: 1,3-dipolar cycloaddition, photochemical rearrangement, treatment with tert-butylamine constitutes a new route to pyrimidine derivatives from 2H,4H,7H-1,3-dioxepine.

scholarly journals A domino reaction for generating β-aryl aldehydes from alkynes by substrate recognition catalysis

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Weiwei Fang ◽  
Felix Bauer ◽  
Yaxi Dong ◽  
Bernhard Breit
Keyword(s):  
Substrate Recognition ◽  
Domino Reaction ◽  
Chemical Transformations ◽  
Reaction Sequence ◽  
Reaction Conditions ◽  
Consecutive Reaction ◽  
Aryl Aldehydes ◽  
Rh Catalyst ◽  
Catalyst Systems ◽  
Step Control

Abstract The development of universal catalyst systems that enable efficient, selective, and straightforward chemical transformations is of immense scientific importance. Here we develop a domino process comprising three consecutive reaction steps based on the strategy of supramolecular substrate recognition. This approach provides valuable β-aryl aldehydes from readily accessible α-alkynoic acids and arenes under mild reaction conditions, employing a supramolecular Rh catalyst containing an acylguanidine-bearing phosphine ligand. Furthermore, the synthesis of a key intermediate of Avitriptan using this protocol is accomplished. The first step of the reaction sequence is proved to be the regioselective hydroformylation of α-alkynoic acids. Remarkably, molecular recognition of the ligand and the substrate via hydrogen bonding plays a key role in this step. Control experiments indicate that the reaction further proceeds via 1,4-addition of an arene nucleophile to the unsaturated aldehyde intermediate and subsequent decarboxylation.

The Hydrosilylation and Cyanosilylation of Ketones Catalyzed using Metal Borohydrides

2019 ◽  
Vol 16 (2) ◽  
pp. 276-282 ◽  
Author(s):  
Yu Liu ◽  
Duodong Zhang ◽  
Yangyang Ma ◽  
Jiayun Li ◽  
Ying Bai ◽  
...  
Keyword(s):  
Carbonyl Compounds ◽  
Reaction Rate ◽  
Biologically Active ◽  
High Conversion ◽  
Similar Reaction ◽  
Reaction Conditions ◽  
Efficient Procedure ◽  
Hydrosilylation Reaction ◽  
One Step ◽  
Relative Catalytic Activity

Aim and Objective: The hydrosilylation reaction of carbonyl compounds has emerged as a powerful method in organic synthesis. The catalytic hydrosilylation of ketones is a valuable transformation because it generates protected cyanosilylation reaction of carbonyl compounds is an efficient procedure for the synthesis of silylated cyanohydrins, which are readily converted into useful functionalized compounds, such as cyanohydrins, α-hydroxy acids, β-amino alcohols and other biologically active compounds. Materials and Methods: A facile, economic and efficient method has been developed for the hydrosilylation and cyanosilylation of ketones using metal borohydrides. A series of silylated ethers and silylated cyanohydrins can be isolated via direct distillation. Results: The catalytic properties of a range of metal borohydrides in the hydrosilylation reaction of acetophenone with diphenylsilane were investigated. The relative catalytic activity of the borohydride catalyst studied was as follows: (CH3)4NBH4> (PhCH2)(CH3)3NBH4> (CH2CH3)4NBH4> (CH3CH2CH2CH3)4NBH4> NaBH4> KBH4> LiBH4. The cyanosilylation of acetophenone using trimethylsilyl cyanide (TMSCN) in the presence of NaBH4 occurred under similar reaction conditions. An excellent reaction rate and high conversion were obtained. Conclusion: The metal borohydride-catalyzed hydrosilylation alcohols in one step. The and cyanosilylation of ketones could be carried out smoothly under mild reaction conditions. Among the metal borohydrides studied, an excellent reaction rate and high conversion were obtained using NaBH4, NaBH (CH2CH3)3 or (alkyl)4 NBH4 as the reaction catalyst.

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