Chemistry of heteroanalogs of isoflavones 13. 1,3-Benzodioxan analogs of flavonoids

Some 1,3-benzodioxan analogs of chalcones and their epoxides have been obtained, and used to prepare pyrazolines and novel flavone and flavanone analogs of flavolignan (sylibin). The PMR spectra of novel compounds are shown and discussed, together with the results of preliminary biological tests.For Communication 12, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 879–887, July, 1992.     

Chemistry of heteroanalogues of isoflavones. 15. Synthesis and study of the reaction of lanthanide

2-Ethyl substituted isoflavones have been synthesized. 7-Isopropyloxyisoflavones carrying 1,3-benzodioxole and 1,4-benzodioxan nuclei have been obtained from them. The spectral characteristics of the compounds obtained are discussed. The reaction of several of the products with various lanthanide shift reagents (LSR) has been studied. The preferred conformation of compounds in solution has been determined. It was shown that optically active LSR must not be used for obtaining quantitative data on the molecular conformation of a substrate due to the lack of effective axial symmetry in the adduct.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1631–1637, December, 1993.     

Synthesen von Heterocyclen, 140. Mitt.: Zur Chemie cyclischer Carbonate

Zusammenfassung 2,4-Dioxo-1,3-benzodioxan (1) reagiert mit Benzaldazin, Benzoxazol und Benzothiazol unter Verlust von CO₂ zu den Heterocyclen3 bis5. Analog verhält sich 2,4-Dioxo-3,1-benzoxathian (2).

---

Syntheses of heterocycles, CXL: Chemistry of cyclic carbonates

2.4-Dioxo-1.3-benzodioxan (1) reacts with dibenzal hydrazine, benzoxazole, and benzthiazole under the loss of CO₂ yielding the heterocyclic compounds3–5. 2.4-Dioxo-3.1-benzoxathian (2) reacts in a similar way.

     

Synthetic analogs of natural flavolignans VII. Synthesis of 1,3-benzodioxane analogs of dehydrosilybin

Structural analogs of dehydrosilbyn have been obtained from 1,3-benzodioxane derivatives of chalcones. Their structures have been confirmed by their PMR spectra.Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 623–625, September–October, 1994.     

Synthetic and modified isoflavonoids. VII. Synthesis of benzodioxocane analogs of pseudobaptigenin

Benzodioxocane analogs of pseudobaptigenin have been synthesized, and their structures have been shown by chemical transformations and PMR spectra.Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 223–226, March–April, 1994.     

Synthetic analogs of natural flavolignans. II. A new synthesis of benzodioxepane analogs of silandrin and hydnocarpin

Benzodioxepane analogs of chalcones have been obtained from which analogs of natural flavolignans — silandrin and hydnocarpin — have been synthesized. The PMR spectra of the new substances are given and are discussed.KIEN, Karakalpak Division, Academy of Sciences of the Republic of Uzbekistan, Nukus. Taras Shevchenko Kiev University, Ukraine. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 480–483, July–August, 1994.     

Synthetic analogs of natural flavolignans. IV. Synthesis of benzodioxocane analogs of silandrin and hydnocarpin

1,6-Benzodioxocane analogs of chalcones have been synthesized. From them have been obtained benzodioxocane analogs of silandrin and hydnocarpin. The PMR spectra of the substances synthesized are given and are discussed.Taras Shevchenko Kiev University, Ukraine. KIEN, Karakalpak Division, Academy of Sciences of the Republic of Uzbekistan, Nukus. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 490–493, July–August, 1994.     

Synthetic analogs of natural flavolignans. V. A new synthesis of 6-halogeno-1,3-benzodioxane analogs of silandrin and hydnocarpin

6-Halogeno-1,3-benzodioxane analogs of chalcones have been synthesized by various methods. Flavanone and flavone analogs of silandrin and hydnocarpin have been obtained from them. The structures of the new flavonoids have been shown by their PMR spectra.KIEN Karakalpak Division, Academy of Sciences of the Republic of Uzbekistan, Nukus. Taras Shevchenko Kiev University, Ukraine. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 494–498, July–August, 1994.     

Synthetic and modified isoflavonoids. VI. Synthesis of analogs of pseudobaptigenin with ester groups

Derivatives of pseudopbaptigenin and of its benzodioxane and benzodioxepane analogs containing an ethoxycarbonyl group in position 2 have been synthesized.Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 220–223, March–April, 1994.     

Synthesis and hypotensive activity of new amino derivatives of terpenoids and their structural analogs

Thirty-five new salts of amino ester derivatives of terpenoids have been synthesized and their influence on the level of arterial pressure has been investigated.Institute of Physical Organic Chemistry, BSSR Academy of Sciences, Minsk. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 190–193, March–April, 1988.     

Synthesis of new analogs of valinomycin and their properties. I

Conclusions 1. The synthesis of five valinomycin analogs differing by the configurations of the amino-acid and hydroxy-acid residues and also by the volumes of the radicals of the hydroxy-acid residues has been effected.2. The stability constants of the complexes of these analogs with potassium ions in ethanol solution have been determined.3. The antimicrobial activities of the compounds obtained have been studied and a correlation has been found between the degree of activity and stability of the complexes with K⁺.M. M. Shemyakin Institute of the Chemistry of Natural Compounds, Academy of Sciences of the USSR. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 233–240, March–April, 1974.     

Pheromones of insects and their analogs

Dodec-8Z-en-1-ol (VIII) and tetradec-8Z-en-1-ol (IX) and the corresponding acetates (X and IX) — components of the sex pheromones of many species of Lepidoptera — have been synthesized from cyclooctene (I) in three stages. The ozonolysis of (I) (–70°C, CH₂Cl₂-MeOH, NaHCO₃; –20°C, Ac₂O/Et₃N) led to methyl 8-oxooctanoate (II). The DNPH of (II), (III), mp 59–61°C. The coupling of (II) with n-C₃H₁₇ CH=PPh₃ (IV) or with n-C₅H₁₁ CH=PPh₃ (V) (–70°C, 2 h; 25°C, 15 h, Ar) gave the methyl esters of dodec-8Z-enoic (VI) and tetradec-8Z-enoic (VII) acids, respectively. The reduction of (VI) and (VII) [(i-Bu)₂AlH, 0°C, 2 h; 25°C, 15 h] gave the corresponding alcohols (VIII) and (IX) by the acetylation (Ac₂O-Py, 25°C, 24 h) of which, (X) and (XI), were obtained. The yields (%): (II) 80, (VI) 45, (VII) 60, (VIII) 95, (IX) 90, (X) 75, (XI) 74. The IR and PMR spectra of compounds (II) and (VI–XI) are given.Institute of Chemistry, Bashkir Scientific Center, Urals Branch, Academy of Sciences of the USSR, Ufa. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 276–279, March–April, 1989.     

Synthesis of analogs of natural isoflavones from 2,4-dihydroxydeoxybenzoins

A number of analogs of natural isoflavones have been synthesized. The starting materials were 2,4-dihydroxydeoxybenzoins obtained under modified conditions of the Houben-Hoesch reaction. The yields of the isoflavones synthesized were 63–69%. All the analogs of natural flavones possess a pronounced hypolipidemic action.Pyatigorsk Pharmaceutical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 781–784, November–December, 1985.     

Theoretical calculations and vibrational spectra of 1,4-benzodioxan in its S(1)(pi, pi*) electronic excited state

The structure and vibrational frequencies of 1,4-benzodioxan in its S₁(π, π^*) electronic state have been calculated using the GAUSSIAN 03 and TURBOMOLE programs. The results have been compared to experimental data and also to the ground state. Structural data for the T₁(π, π^*) state have also been calculated. The theoretical frequencies agree very well with the experimental values for the S₀ electronic ground state but are less accurate for the S₁ excited state. Nonetheless, they provide valuable guidance for excited state calculations.     

Synthetic and modified isoflavonoids XIX. Synthesis of 8-methyl-substituted analogs of pseudobaptigenin

New 8-methyl-substituted chromones with 1,4-benzodioxane and 1,5-benzodioxepane nuclei in position 3 have been synthesized. Their structures have been confirmed by chemical transformations and PMR spectra.Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 370–374, May–June, 1997.     

Synthetic and modified isoflavonoids XVI. The interaction of synthetic isoflavone analogs with hydroxylamine

Under the action of hydroxylamine, 1,3-benzodioxolane, 1,4-benzodioxane, and 1,5-benzodioxepane analogs of isoflavones recyclize into 5-(2-hydroxyphenyl)isoxazole derivatives. Their structures have been shown by their PMR spectra.Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 633–636, September–October, 1994.     

New synthesis of [8-arginine] vasopressin and its de-9-glycine analogs

A unified scheme is proposed for the synthesis of [8-arginine]vasopressin (I), de-9-glycine[8-arginine]vasopressin (II), and de-9-glycinamide[8-arginine]vasopressin (III) which has been developed on the basis of the tetrapeptide Gln-Asn-Cys(Bzl)-Pro and other homologous fragments of neurohypophyseal hormones as common initial and intermediate compounds. The free dithiols obtained by the reduction of protected derivatives of (I)–(III) by sodium in liquid ammonia have been oxidized to the corresponding cyclic disulfides (I)–(III) with the aid of 1 M H₂O₂ at 0–5°C and pH 8.5. The vasopressor activities of (I)–(III) are, respectively 470 ± 20, 1.7, and 0.5 IU/mg (rat, in vivo).Institute of Organic Synthesis, Latvian SSR Academy of Sciences, Riga. Translated from Khimiya Prirodnykh Soedinenii, No.3, pp. 433–439, May–June, 1988.     

Synthetic and modified isoflavonoids XVIII. Synthesis of 7-isopropoxy-substituted analogs of pseudobaptigenin

7-Isopropoxy derivatives of isoflavones have been synthesized from 1,3-benzodioxole, 1,4-benzodioxane, and 1,4-benzodioxepane analogs of pseudobaptigenin. Their structures have been confirmed by PMR.Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 365–369, May–June, 1997.     

Heterocyclic analogs of pleiadiene

The behavior of N-methyl derivatives of perimidine (I), aceperimidine (VI), aceperimidylene (VII), naphth[2,3-d]imidazole (V), benzimidazole (II), and 1H- and 3H-naphth[1,2-d]imidazoles (III, IV) with respect to n-butyllithium was studied. Compounds I and V–VII add n-butyllithium to the C=N bond to give 2-n-butyl-2,3-dihydro derivatives, whereas II–IV are metallated to give 2-lithio derivatives. The different reactivities of I, V–VII, and II–IV are explained by the reduced aromatic character and high polarization of the C=N bond in I and V–VII. The investigated compounds are arranged in the following order with respect to the ease of undergoing basic deuterium exchange at the C-H bond V>II>III>IV>VII>I>VI. There is no correlation between the rate of deuterium exchange and the behavior of I–VII with respect to butyllithium.See [1] for communication XXX.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1544–1548, November, 1977.     

Synthesis of phosphinic and phosphoric analogs of aspartic acid

Approaches to the synthesis of 1-amino- and 2-amino-2-carboxyethylphosphinic and-phosphoric acids have been studied. A convenient method for the preparation of phosphinic acids is the reactions of ethyl diethoxymethylphosphonite with ethyl acetamidomethylenemalonate and ethyl 2-acetamidoacrylate.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 2066–2069, August, 1996.