3-O-乙酰基-4,6-二-O-苄基-1,2-环丙烷葡萄糖的合成

以葡萄糖为起始原料制得苄基葡萄烯糖,再经Ferrier重排、双羟化反应、选择性磺酰化、羟基保护和在碱性条件下关环反应合成了3-O-乙酰基-4,6-二-O-苄基-1,2-环丙烷葡萄糖.其中5个中间体为新化合物,其结构经1H NMR,13C NMR和HR-MS表征.     

A Facile One-Pot Synthesis of 2,3′-Anhydro-2′-Deoxyuridines via 3′-O-Imidazolylsulfonates

Continued interests in the novel synthetic methods of the pivotal compound, 2,3′-anhydro-2′-deoxyribonucleosides (7) uncovered a facile one-pot conversion of 5 with 1,1′-sulfonyldiimidazole in basic conditions to 7 with almost quantitative yields (91–99%).     

A Facile Synthesis of 3,4-Dialkoxythiophenes

Dialkylation of diethyl 3,4-dihydroxythiophenedicarboxylate followed by ester hydrolysis and acid decarboxylation provides a general route to 3,4-dialkoxythiophenes.     

A Facile Synthesis of 1,2-Disubstituted Aziridines

In spite of the fact that a number of methods are available for the preparation of aziridines, general synthetic routes leading to 1,2-disubstituted aziridines remained laborious in most cases^(2-6). A convenient and versatile synthesis is desirable in order to permit studies of this important biologically active heterocyclic system.     

Facile Synthesis of 1,2-Dialkyl-3-Phenyl-4-Quinolinones

The synthesis of 1,2-dialkyl-3-phenyl-4-quinolinones (1) is readily accomplished by a low-temperature reaction of an N-alkylisatoic anhydride with the therraodynamic potassium enolate of phenyl-acetone. The reaction has also been extended to encompass the synthesis of the more complex 2-(3-hydroxy-propyl)-3-(4-fluorophenyl)-1-methyl-4(1H)-quinolinone (10).     

A Facile Synthesis of 1,1,6-Trimethyl 1,2-Dihydronaphtalene

an easy two-step preparation of 1,1,6-trimethyl 1,2-dihydronaphtalene from α-ionone via 1,1,6-trimethyl 1,2,3,4-tetrahydronaphtalene is described.     

A Facile Synthesis of 3,4‐Benzo‐β‐carbolines

Abstract

A convenient method for the synthesis 3,4‐benzo‐β‐carbolines (10) from the corresponding N‐phenylsulfonyl‐3‐bromo‐N′‐arylisogramines (5) via radical mediated cyclization methodology has been reported.     

Facile Synthesis of Furan-3,4-diacetates

A procedure for bis-cyclopropanation of furans with ethyl diazoacetate or methyl α-diazopropionate under dirhodium-tetraacetate catalysis is presented. Treatment of the products with ethanolic HCl furnished furan-3,4-diacetates.     

A Facile Synthesis of 6-Substituted Benzimidazo[1,2-c]-Quinazolines Under Microwave Irradiation

Microwave irradiation promoted the high-yield cyclocondensation of ortho esters (1a-f) with 2-(2-aminophenyl)benzimidazole (2), as the catalyst was no longer needed.     

Synthesis of some 6-S-heterocyclic derivatives of 1,2:3,4-di-O-isopropylidene-α-D-galactopyranose

We applied nucleophilic substitution to 6-O-tosyl-1,2:3,4-di-O-isopropylidene-α-D-galactopyranose using sulphur nucleophiles and obtained 6-S-derivatives of 1,2:3,4-di-O-isopropylidene-α-D-galactopyranose. We present the physical and spectroscopic characterization of these heterocyclic compounds as well as other related compounds obtained by substitution, using other substrates. The conformational studies of all products are presented and discussed.     

A Facile Synthesis of Pyrazolo[3,4-b]pyridines

Pyrazolo[3,4-b]pyridines (4) and (5) have been obtained by the condensation of 3-(alkyl/aryl)-5-amino-1-phenyl-1H-pyrazole-4-carboxaldehydes (3) with active methylene compounds viz: diethyl malonate and malononitrile.     

A Facile Synthesis of Ethyl-2-Methyl-5h-Chromeno[3,4-c]Pyridine-1-Carboxylates

4-Chloro-2H-3-chromene carbaldehydes (2a-i) on reaction with ethyl-3-aminocrotonate 3 gives ethyl-2-methyl-5H-chromeno[3,4-c]pyridine- 1- carboxylates 4a-i in good yields.     

A Facile Synthesis of 1,2:3,4:5,6-Tri-O-Isopropylidene-D-Gluconate–A Convenient Precursor of the Open Chain form of D-Glucose

Abstract

Condensation of D-glucono-1,5-lactone (1) with acidified acetone yields in low yield, among other products, 1,2:3,4:5,6-tri-O-isopropylidene-D-gluconate (2).^1,2 Reaction of 2 with sodium methoxide in methanol gives methyl 3,4:5,6-di-O-isopropylidene-D-gluconate³ (3); this compound was prepared recently by Chittenden and co-workers³ directly from 1 (by reaction of 1 with acetone and dimethoxypropane). It is easily transformed³ into 2,3:4,5-di-O-isopropylidene-D-arabinose (4).     

A New Facile Synthesis of 5-Alkyl-2-Aryl-3H-Pyrazol-3-Ones

The title compounds widely used in construction of pigments and antimaterials are most usually prepared by condensation of arylhydrazines and β-keto esters ^1,2. Although a number of 5-methyl and aryl derivatives have been obtained, other 5-alkyl-3-pyrazolones are rarely mentioned in literature ³ because of the lack of a convenient method to prepare the approperate β-keto esters used in condensation.     

A Facile Synthesis of Pyrido [1,2-a] Benzimidazoles

The synthesis and characterisation of some of the new pyrido [1,2-a] benzimidazoles from 1H-benzimidazole-2-acetonitrile and diethyl ethoxy methylene malonic ester.     

A Facile Synthesis of 3,7-Disubstituted-4,8-dimethyl-2,6-dioxo-2H,6H-benzo[1,2-b:3,4-b′]dipyrans and Their Antifeedant Activity

The synthesis, characterisation and antifeedant activity of some new dicoumarins prepared from 2,4-diacetyl resorcinol has been reported.     

Facile Alternative Synthesis of 1-Alkyl-5-alkylamino-6-phenethyluracils

A short alternative synthesis of 1-alkyl-5-alkylamino-6-phenethyluracil is described in 47% overall yield of 1a via five steps starting from commercially available 6-methyluracil.     

Synthesis of 3-cyano-4-aryl-5-ethoxycarbonyl-6-methyl-3,4-dihydropyridine-2-thiones

The condensation of ethyl arylidenacetoacetate with cyanothioacetamide and of arylidenecyanothioacetamides with ethyl acetoacetate or of arylidenecyanothioacetamides with ethyl -aminocrotonate gave 3-cyano-4-aryl-5-ethoxycarbonyl-6-methyl-3,4-dihydropyridine-2-thiones. PMR spectroscopy showed that the 3-cyano-4-aryl-3,4-dihydropyridine-2-thiones are formed as a mixture of cis and trans isomers.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 95–102, January, 1985.