Synthesis of Isonucleoside 5′-Triphosphates

Abstract

A series of isonucleoside 5′-triphosphates were synthesized via a rapid and efficient method. The structures of the triphosphates (8a–8d) were characterized by ³¹P NMR and TOF-MS.     

Synthesis of 5-Deoxy-5-Acyloxyiminoavermectin B1 Derivatives

The avermectins1 are a unique collection of naturally occurring macrocyclic lactones with broad spectrum of anthelmintic and insecticidal activities. Their remarkable biological activity and complex molecular architecture stimulated significant interest in the scientific community. Much research has been carried out on these compounds. Many derivatives of avermectin have much more bioactivities and have been commercially utilized2-5. Here we describe the synthesis of 5-deoxy-5-acyloxyimi…     

The Synthesis of 1-Aryl-5-Fluorouracil

5-Fluorouracil (5-Fu,1)1 is an important antitumor drug. Some derivatives2,3 have shown better therapeutic efficacy than 5-Fu. In order to find much more better antitumor drugs of its derivatives, several attempts have been made and many different types of its derivatives have been prepared at N1, N3 position4~7. Moreover, several different ways have been used for alkylation of 5-Fu7~10. However, up to now, the arylation of 5-Fu at N1 or N3 position hasn't been reported, and the compound o…     

Synthesis of 1-acyl-5-aryl biurets

Fourteen new 1-acyl-5-aryl biurets were synthesized by the reaction of aryl ureas with acylisocynantes. The latter was obtained from acyl chloride and lead cyanate in dichloromethane, using pyridine as catalyst. The structures of compounds 3a-n were confirmed by IR,1H NMR and MS spectra.     

Synthesis of Trideuteriomethyl 5-Deuterium-β-D-Mannopyranoside

Abstract

The title compound was prepared by first converting trideuteriomethyl 2,3,4-tri-O-benzyl-β-D-mannopyranoside to a 6-bromo-6-deoxy derivative which on elimination by using DBU (1,8-diazabicyclo[5.4.0]undec-7-ene) or DBN (1,5-diazabi-cyclo[4.3.0]non-5-ene) gave a hex-5-enopyranoside derivative. The deuteroboration of the hex-5-enopyranoside followed by oxidation and subsequent deblocking produced trideuteriomethyl 5-deuterium-β-D-mannopyranoside.     

Convenient Synthesis of 5‐Aryl Uracils

A convenient one‐step synthesis of 5‐aryl uracils has been developed. The procedure involves heating ethyl 3‐hydroxy‐2‐arylpropenate with urea at 130°C, followed by base‐catalyzed cyclization. The method is simple and high yielding.     

Synthesis of 5α-Iodo-6-one Steroids

Abstract: The synthesis of 5-iodo-5α-cholestan-6-one (6), its 3β-acetoxy-(7) and 3β-chloro-(8) analogues, 3β-acetoxy-5-iodo-5α-stigmastan-6-one (9) and its 3β-chloro-(10) analogue by the reacion of silver chromate-iodine and pyridine with the corresponding steroidal olefins (1-5) is described. The structures of these products have been established on the basis of their elemental, analytical and spectral data.     

Convenient Synthesis of Uridine 5′ - Oxyphosphorane

Uridine 5′-oxyphosphorane was synthesized by the reaction of 2′, 3′-di-O-acteyluridine 5′-diisopropyl phosphite with tetrachloro-1, 2-benzoquinone.     

Solvent-free Synthesis of 5-Azacytosine with Microwave Activation

Azacytosine (4-amino-1,2-dihydro-1,3,5-triazin-2-one) is a very important intermediate in the synthesis of 5-azacytidine which showed remarkable bacteriostatic and cytostatic activity as well as against T-4 lymphoma and L-1210 leukemia in mice. Starting with N-cyanoguanidine (dicyandiamide) and formic acid, under the solvent-free microwave activation, we synthesized 5-azacytosine in short time (4min) with good yield (60.4%). The structure of the product was confirmed by HNMR and Elemental a…     

Synthesis of Stigmastane 5β-Hydroxy-6-ketosteroids

-Sitosterol 1 and the intermediate 5-hydroxy-6-ketosteroids 2 and 3 were used to synthesize 5-hydroxy-6-ketosteroid oximes 4 and 5. Dehydration of 5 fromCinachyrellasponges forms (24R,6E)-24-ethylcholest-6-hydroximino-4-en-3-one 6, a steroidal oxime     

Synthesis of Chromium (Ⅲ) 5-aminosalicylate

As we all known that diabetes is a chronic disease with major health consequences 。 Research has revealed that the occurrence of diabetes have great thing to do with the chromium deficient。Almost 40 years after the first report of glucose tolerance factor(GTF) [1] ,no conclusive evidence for an isolable ,biologically active form of chromium exited。Three materials have been proposed to be the biologically active form of chromium:“glucose tolerance factor”,chromium Picolinate and lo…     

Synthesis of New 5‐Substituted Pyrimidine Acyclonucleosides

Acyclonucleosides of pyrimidine were prepared by condensing appropriately silylated 5‐substituted pyrimidines with an acyclic side chain in the form of an acetylated haloalkoxyalcohol and subsequent removal of the protecting acetyl group in base. Also, acyclonucleosides with a 1‐ethoxymethyl side chain have been investigated. The activity against hepatitis B virus (HBV) has been tested.     

First Total Synthesis of 5_α-Hydroxy-isopterocarpolone

Sesquiterpenic compounds of the Eudesmane family have attracted considerable attention due to their intriguing biological properties1,2, particularly significant antifeedant activity, cell growth inhibitory and plant growth regulating activities.In 1996, J. Hu and co-workers3 had isolated eudesmane sesquiterpene 5?-hydroxy-isopterocarpolone 1 from the aerial parts of chinese folk medicine Artemisia eriopoda and elucidated its structure by spectropic methods. Herein, we reported the first tota…     

Total Synthesis of Two 4, 5-Dioxo-seco-eudesmane Sesquiterpenes

A facile synthetic route to two seco-eudesmane, 4, 5-dioxo-10-epi-4, 5-seco-γ-eudesmane (1) and 4, 5-dioxo-10-epi-4, 5-seco-γ-eudesmol (2) from ( )-dihydrocarvone has been described. Avoiding expensive reagents, this highly economic method especially suits for the synthesis of 4, 5-seco-eudesman-type and ophianon-type sesquiterpenes with a double bond at position 11 and 12.     

Synthesis and conversions of metallocycles. 9. Synthesis of polycyclic aluminocyclopentanes with the participation of (η5-C5H5)2ZrCl2

The Cp₂ZrCl₂-catalyzed (Cp=⁵-C₅H₅) stereoselective cyclometalation of norbornenes and norbornadienes with AlEt₃ was carried out. It led in one stage to the preparation of polycyclic aluminocyclopentanes (ACP). It was shown that the ACP synthesized can be converted into polycyclic thiophanes under the action of elementary sulfur.For previous communication, see [1].Institute of Chemistry, Bashkir Scientific Center, Ural Branch, Academy of Sciences, 450054 Ufa. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 2, pp. 386–391, February, 1992.     

Synthesis of 5-Alkenyl-2′-Deoxyuridines Via Organostannanes

The palladium-catalysed coupling of 3,5 Di-O-p-toluoyl-5-iodo-2′ -deoxyuridine with functionalized and non-functionalized alkenylstannanes gave moderate to good yields of the corresponding 5-alkenyl-2 -deoxyuridines.     

Synthesis and Characteristics of a New Molybdoantimonate KSbMoO_5

1 INTRODUCTION Great efforts have been made for the discovery of microporous solids due to their rich structural chemi- stry and wide applications in some commercial pur- poses as ion exchanger, absorbent, and catalyst[1]. Since many properties of porous materials depend on their composition and architecture, recent attention has been paid to incorporating other main group and tra- nsition metals into open frameworks, and plenty of materials are reported to contain polyhedra, such as [X…     

Synthesis of 5 β-Chloro-4α-methoxysantonin Oxime

The newderivative 5-chloro-4-methoxysantonin oximewasprepared from5-chloro-4-methoxysantonin by reaction with hydroxylamine hydrochloride in the presence of pyridine. The structure was established by IR, UV, and PMR spectroscopies.     

Synthesis of 5—Deoxy—5—Acyloxyiminoavermection B1 Derivatives

Four 5-deoxy-5-acyloxyiminoavermectin B1 derivatives 4a-d were synthesized via three steps from avermenction B1 and their biological activities were tested against Heliothis armigera, Laphygma exigua and Musca domestica.