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 analogs of natural flavolignans. III. Synthesis of 6-carboxy-1,3-benzodioxane analogs of silandrin and hydnocarpin

Chalcones containing a 6-carboxy-1,3-benzodioxane fragment and, from them, flavanone and flavone analogs of silandrin and hydnocarpin have been synthesized. The structures of the compounds obtained were confirmed 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. 484–489, 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 analogs of natural flavolignans VIII. Synthesis of 6-chloro-1,3-benzodioxane, 1,4-benzodioxane, 1,5-benzodioxepane, and 1,6-benzodioxocane analogs of 4-thioflavone

1,3-Benzodioxane, 1,4-benzodioxane, 1,5-benzodioxepane, and 1,6-benzodioxocane analogs of 4-thioflavone have been synthesized.Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 375–378, May–June, 1997.     

Synthetic analogs of naturally occurring flavolignans. XI. Reaction of synthetic flavone analogs with hydrazine hydrate and its derivatives

Reactions of 1,3-benzodioxane and 1,4-benzodioxane analogs of flavones with hydrazine derivatives are studied. The hydrazines recyclize the new flavones into 3,5-diarylpyrazoles. Their PMR spectra confirm their structures.Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 40–41, January–February, 2000.     

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.     

Synthetic analogs of natural flavolignans. III. Synthesis of 6-carboxy-1,3-benzodioxane analogs of silandrin and hydnocarpin

Chalcones containing a 6-carboxy-1,3-benzodioxane fragment and, from them, flavanone and flavone analogs of silandrin and hydnocarpin have been synthesized. The structures of the compounds obtained were confirmed 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. 484–489, July–August, 1994.     

Synthesis and reactions of 6-hydroxy-2,4-dimethyl-1,3-benzodioxane

The reaction of hydroquinone and acetaldehyde in a mixture of acetic and hydrochloric acids (31) at 0–5 °C gives 6-hydroxy-2,4-dimethyl-1,3-benzodioxane, which forms ethers and esters at the hydroxy group, undergoes diazo coupling, and, under the influence of acids, undergoes polycondensation with opening of the 1,3-dioxane ring.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1195–1198, September, 1983.     

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.     

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 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.     

Synthetic and modified isoflavonoids XVII. Interaction of synthetic analogs of isoflavones with guanidine

Under the influence of guanidine, 1,3-benzodioxolane, 1,4-benzodioxane, and 1,5-benzodioxepane analogs of isoflavone are converted into 2-aminopyrimidine derivativesTranslated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 636–640, September–October, 1994.     

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.     

Synthetic and modified isoflavonoids XV. Interaction of synthetic analogs of isoflavones with hydrazine hydrate and its derivatives

The reactions of 1,3-benzodioxolane, 1,4-benzodioxane, and 1,5-benzodioxepane analogs of isoflavones with hydrazine derivatives have been studied. It has been found that under the action of hydrazines the new isoflavones recyclize into 3,4-diarylpyrazones. Their structures have been confirmed by their PMR spectra.Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 629–633, September–October, 1994.     

Synthesis of new biheterocycles containing a 1,4-benzodioxane fragment

The reaction of 1,4-benzodioxane-2-carbonyl chloride with 5-(4-aminophenyl)-1,3,4-oxa- and -thiadiazole-2-thiols afforded new biheterocyclic compounds which were converted into the corresponding S-benzyl derivatives by treatment with benzyl chloride. 5-(4-Aroylaminophenyl)-1,3,4-oxa(thia)diazole-2-thiols reacted with 2-bromomethyl-1,4-benzodioxane to give compounds in which the 1,4-benzodioxane nucleus and fivemembered heterocycle are linked through a CH₂S bridge.     

Synthetic and modified isoflavonoids XIV. Mannich bases and their salts in a series of synthetic isoflavone analogs

Mannich bases and their hydrochlorides have been obtained from 1,3-benzodioxolane, 1,4-benzodioxane, and 1,5-benzodioxepane analogs of pseudobaptigenin. The PMR spectra of the compounds obtained are given and are discussed.Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 625–629, September–October, 1994.     

Synthetic and modified isoflavonoids V. Synthesis of 2-trifluoromethyl-substituted analogues of pseudobaptigenin

New two-trifluoromethylchromones with 1,3-benzodioxole and 1,4-benzodioxane nuclei in position 3 have been synthesized.Taras Shevchenko Kiev University KIEN. Karakalpak Division, Uzbekistan Academy of Sciences, Nukus. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 820–822, November–December, 1993.     

Behavior of 6-cyclopropyl- and 6-bromo-7-cyclopropyl-1,4-benzodioxanes under electrophilic substitution reaction conditions

Bromination of 6-cyclopropyl-1,4-benzodioxane occurs with concerted orientation of the ethylenedioxy group and the cyclopropyl radical for the least sterically hindered position of the aromatic ring. Nitration of 6-bromo-7-cyclopropyl-1,4-benzodioxane does not lead to products of substitution of the hydrogen atom in the 5 or 8 position of the 1,4-benzodioxane, but rather to the nitrodebromination product: 7-nitro-6-cyclopropyl-1,4-benzodioxane. The anomalous behavior of the bromo-substituted benzodioxane is explained by the predisposition of the carbon atom bonded to the bromine towardipso attack by an electrophile.M. V. Lomonosov Moscow State University, Moscow 119899. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 618–620, May, 1998.     

Diastereomeric 2-aminomethyl-1,4-benzodioxane mandelates: phase diagrams and resolution

The diastereomeric salts of (R)- and (S)-2-aminomethyl-1,4-benzodioxane with unichiral mandelic acid form a simple eutectic, whose binary phase melting point diagram shows the unique eutectic at 0.35 M ratio of the less soluble diastereomer. Such an eutectic composition, near to 0.5, is consistent with the modest efficiency previously reported for their separation via crystallization from ethanol/ethyl acetate. However, the ternary solubility phase diagram, obtained from solubility measurements in methanol, shifts the eutectic to a lower molar ratio (0.10) of the less soluble diastereomer, thus indicating an optimal resolvability of the diastereomeric mandelates. This was confirmed by the highly efficient resolution of racemic 2-aminomethyl-1,4-benzodioxane with (R)-mandelic acid via a single crystallization from methanol. The ready availability of both the racemic substrate and the resolving acid makes this simple and efficient resolution procedure very attractive to obtain the enantiomers of 2-aminomethyl-1,4-benzodioxane, which are important synthetic intermediates.     

1,4-苯并二噁烷类新木脂素Eusiderin G的全合成

以没食子酸甲酯为原料,经过6步反应(总产率为24%),对1,4-苯并二噁烷类新? 局靥烊徊顴usiderinG进行了全合成。合成反应的关键是在强酸性离子交换? 髦呋拢肿幽诘拇剪腔敕郁腔浞⑸阉从Γ鼗沸纬?,4-苯并二噁烷骨架化合物。该合成路线具有简便易行、产率较高、副反应少的特点,可适用于其它具有生理活性的1,4-苯二噁烷类化合物的合成。