Synthesis of chalcone analogs containing a pyrrole ring

Crotonaldehyde-type condensation in alkaline medium of 2-acetylpyrrole or pyrrole-2-aldehyde with aromatic or heterocyclic aldehydes and methyl ketones gives a number of hitherto undescribed pyrrole analogs of chalcone, and their 2, 4-dinitrophenylhydrazones are prepared.     

Synthesis of heterocyclic analogs of chalcone containing the selenophene ring

Crotonaldehyde-type condensation using alkaline or acid catalyst is used to synthesize 14 chalcone analogs containing in addition to the selenophene ring, a number of other heterocyclic groups. A Michael adduct is shown to be formed by reaction of 2-acetylselenophene with 2-pyridine aldehyde.     

Conformation of thiophene analogs of chalcone containing a naphthalene ring

It has been shown on the basis of dipole moment and IR spectroscopic measurements of thiophene-naphthalene analogs of chalcone that the latter exist in the s-cis form in solutions and have a trans configuration of the substitutents at the double bond and a definite position of the thiophene ring.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1188–1191, September, 1970.     

Synthesis of analogs of ecdysteroids containing an isoxaline ring in the side chain

Starting with poststerone a synthesis was performed of ecdysteroid analogs containing an isoxaline ring in the side chain. The key stages of the route to the target products were Normant reaction and the subsequent 1,3-dipolar cycloaddition of nitrile oxides to 20-hydroxy-20-vinylsteroids.     

Synthesis of alkenoic acid derivatives containing cyclopropane ring,new juvenile hormone analogs

A synthetic method is described for the preparation of new type juvenoids [$\text{2}$].     

Synthesis ofd-provitamins containing a side-chain isozazoline ring

This is the first report of the synthesis of 20-isoxazoline steroids containing a 5,7-diene group by 1,3-dipolar cycloaddition of nitrile oxides to Δ²²-steroids, leading to 20-isoxazolin-5′-ylsteroids, or of steroidal 22-nitrile oxides to low-molecular-weight dipolarophiles, giving 20-isoxazolin-3′-ylsteroids. Institute of Bioorganic Chemistry, Academy of Sciences of Belarus, 220141 Minsk, Belarus. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 267–273, February, 1998.     

Synthesis of heterospirans containing a γ-lactone ring

Reactions of α-ketols with diethyl malonate at the molar ratio 2:1 in the presence of K₂CO₃ were investigated. The heterospiranes obtained contained a dihydrofuran and a γ-lactone rings. The optimum conditions for the synthesis of heterospiranes were found by varying the ratio of the initial compounds: α-ketoalcohol (or 2-ethoxycarbonyl-, 2-methoxycarbonyl-, 2-cyano-3,4,4-trimethyl-2-buten-4-olides), diethyl malonate, K₂CO₃, by varying the environment, and also the temperature and the time of the reaction.     

Synthesis of polynucleotide analogs containing a polyvinyl alcohol backbone

Water soluble homo-base polynucleotide analogues were synthesized in which polyvinyl alcohol and partially phosphonated polyvinyl alcohol constituted the backbones,onto which were grafted uracil or adenine via 1,3-dioxane spacers formed by acetal formation with the 1,3-diol moieties in PVA. The resulting adenine-PVA polynucleotide analogs exhibited hyperchromic effects, which was not the case for the corresponding uracil compounds. Mixtures of the adenine- and aracil PVA-phosphate polynucleotide analogs in solutions exhibited characteristic S-shaped UV-absorbance vs temperature and melting curves with melting points at approximately 40 degrees C.     

Synthesis of binzindene prostaglandins: a novel potent class of stable prostacyclin analogs

The phenols $\text{13}$, $\text{16}$, and $\text{21}$, produced with remarkable regioselectivity by the cyclization of compounds $\text{10}$ and $\text{12}$, have been converted to the benzindene prostaglandin analogs $\text{25}$, $\text{20}$, and $\text{24}$, respectively. Compounds $\text{24}$ and $\text{25}$ are potent prostacyclin mimics.     

Synthesis and study of heteroaromatic ligands containing a pyrimidine ring

5-Hexyl-3-[2-(1H-pyrazol-1-yl)pyrimidin-4-yl]amino-1(2)H-1,2,4-triazoles and 2-(3,5-dipropyl-4-ethyl-1H-pyrazol-1-yl)-6-methyl-4-(5-methyl-1H-pyrazol-1-yl)-aminopyrimidine were synthesized by the reaction of 4-chloropyrimidines with 3-araino-5-hexyl-1H-1,2,4-triazole and 3-amino-5-methyl-1H-pyrazole. Their IR, UV, and PMR spectra were investigated. New methods for the preparation of the intermediates, viz., 2-hydrazino-4(3H)-pyrimidinones and 2-(1H-pyrazol-1-yl)-4(3H)-pyrimidinones, that make it possible to obtain these compounds in higher yields are described.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1673–1677, December, 1980.     

Synthesis of adenosine-based fluorosides containing a novel heterocyclic ring system

A novel class of fluorescent adenosine derivatives (fluorosides) containing the previously unreported 8-(3H-[1,2,3]triazol-4-yl)-9H-purine heterocyclic ring system is reported, with Sonogashira cross-coupling and [3+2]-cycloaddition reactions being the key steps in the synthesis.     

Synthesis and biological activity of permethrinic acid analogs containing various substituents in position 2 of the cyclopropane ring

A number of permethrinic acid ethyl ester derivatives having various substituents [Et, Pr, Ph, Ph(CH₂) _n (n = 1, 2), etc.] in position 2 of the cyclopropane ring were synthesized, and their insecticidal acivity against typhoid flies, rice weevils, and bean aphides, as well as juvenoid activity on flour beetle chrysalises, was studied. The newly synthesized compounds turned out to exhibit weak insecticidal activity against standard insects but pronounced juvenile hormone activity, which differentiates them from permethrinic acid esters.     

Synthesis of a pyrazole prostacyclin

A highly convergent entry to chiral heteroaromatic prostacyclin analogues is outlined.     

Synthesis of tryptamines containing a sulfo group in the benzene ring

It has been shown that sulfophenylhydrazines can be used successfully in a single stage synthesis of tryptamines from arylhydrazines and -chlorocarbonyl compounds.K. A. Timiryazev Agricultural Academy, Moscow 127550, Russia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 623–624, May, 2000.     

Synthesis of a novel prostacyclin analog containing the bicyclo[3.1.0] hexane ring system. Application of molecular mechanics calculations to organic synthesis

The synthesis of a novel prostacyclin analog I has been achieved, incorporating as a key strategic feature a regio-controlled epoxide ring opening (as predicted by MM2 calculations) of a readily available prostaglandin synthon.