Synthetic analogues of Peganum alkaloids. III. Pentamethylenequinazolones

Monosubstituted 5-, 6-, and 8-methoxy-3,4-dihydro-2,3-pentamethylenequinazolones (1–3) have been syntehsized by the condensation of monosubstituted methoxyanthranilic acids with caprolactam. Demethylation with hydrobromic acid gave the corresponding hydroxy compounds [4–6]. When the 6- and 8-methoxy- and 6- and 8-hydroxy-3,4-dihydro-2,3-pentamethylenequinazolones (2, 3, 5, and 6) were reduced with zinc in hydrochloric acid, the corresponding quinazoline derivatives (7–10) were obtained. The melting points of the basis and their hydrochlorides are given. Some features of their UV, mass, and PMR spectra are reported.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 465–469, July–August, 1986.     

Synthetic analogues of Peganum alkaloids VII. Bromine-substituted quinazoline alkaloids and their analogues

The quinazoline bases pentamethylenequinazoline and peganol react with bromosuccinimide in glacial acetic acid to form the corresponding 6-bromoquinazoline derivatives. Some by-products of the bromination reaction have been isolated and characterized. 6-Bromopeganol has been subjected to x-ray structural analysis.Institute of Chemistry of Plant Substances, Uzbekistan Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 233–240, March–April, 1992.     

Synthetic analogues of Peganum alkaloids. V. Peganol from deoxpeganine

Institute of the Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, Vol. 6, pp. 857–858, November–December, 1989.     

Synthetic analogs of Peganum alkaloids VI. Photochemical oxidation of 2,3-polymethylene-quinazoline derivatives

The rates of the photochemical oxidation of quinazoline alkaloids — deoxypeganine, peganine, pentamethylenequinazoline, and peganol — to the corresponding oxo derivatives have been studied. It has been shown by HPLC that the oxidation of deoxypeganine proceeds through a stage of the formation of a carbinolamine (peganol); in the case of its hydrochloride, the reaction takes place by the same scheme but four times more slowly. Tetra- and pentamethylenequinazolines have been synthesized and information on their melting points in the literature has been corrected. In the series trimethylenequinazoline-pentamethyl-enequinazoline-tetramethylenequinazoline the stability falls from left to right.Institute of Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 528–532, July–August, 1991.     

Synthetic analogs of Peganum alkaloids VI. Photochemical oxidation of 2,3-polymethylene-quinazoline derivatives

The rates of the photochemical oxidation of quinazoline alkaloids — deoxypeganine, peganine, pentamethylenequinazoline, and peganol — to the corresponding oxo derivatives have been studied. It has been shown by HPLC that the oxidation of deoxypeganine proceeds through a stage of the formation of a carbinolamine (peganol); in the case of its hydrochloride, the reaction takes place by the same scheme but four times more slowly. Tetra- and pentamethylenequinazolines have been synthesized and information on their melting points in the literature has been corrected. In the series trimethylenequinazoline-pentamethyl-enequinazoline-tetramethylenequinazoline the stability falls from left to right. Institute of Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 528–532, July–August, 1991.     

Synthetic and modified isoflavonoids III. Synthesis of benzodioxane analogues of pseudobaptigenin

Benzodioxane analogues of pseudobaptigenin with alkyl fragments in positions 2 and 6 of the chromone ring have been synthesized from -(1,4-benzodioxan-6-yl)-2-hydroxy-6-alkylacetophenones.Taras Shevchenko Kiev University, KIEN. Karakalpak Division, Uzbekistan Academy of Sciences, Nukus. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 808–814, November–December, 1993.     

Synthetic and modified isoflavonoids III. Synthesis of benzodioxane analogues of pseudobaptigenin

Benzodioxepane analogues of pseudobaptigenin have been synthesized and their structures have been established by chemical transformations, elementary analysis, and PMR spectroscopsy. Taras Shevchenko Kiev University KIEN. Karakalpak Branch, Uzbekistan Academy of Sciences. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 814–820, November–December, 1993.     

Synthetic studies on terpenoids—III: Synthetic approaches to diterpene alkaloids

A stereoselective synthetic route to the bicyclic keto ester 14 from octalin 4 is described. Ketoester 14 is converted to its azide 27 in several steps. Photolysis of 27 produced the lactam 2 whose transformation to lactam 3 is reported.     

Synthetic and modified isoflavonoids. I. Synthetic analogues of pseudo-baptigenin

New isoflavones derived from pseudobaptigenin containing alkyl substituents in position 6 have been synthesized. The structures of the compounds have been confirmed by PMR and IR spectroscopies.Taras Shevchenko Kiev University KIEN. and Karakalpak Division. Academy of Sciences of the Republic of Uzbekistan, Nukus. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 669–674, September–October, 1993.     

Synthetic and modified isoflavonoids. I. Synthetic analogues of pseudo-baptigenin

New isoflavones derived from pseudobaptigenin containing alkyl substituents in position 6 have been synthesized. The structures of the compounds have been confirmed by PMR and IR spectroscopies.