Reactions of 2,3-Dichloro- and 2,3,5-Trichloro-4,4-ethylenedioxy-2-cyclopentenones with Some O-, S-, and N-Nucleophiles

2,3-Dichloro- and 2,3,5-trichloro-4,4-ethylenedioxy-2-cyclopentenones react with allyl and benzyl alcoholates and thiolates and benzylamine to give products resulting from Ad_NE substitution of the 3-chlorine atom, [1,3]-sigmatropic rearrangement, and cleavage of the C¹-C² bond.     

Prostanoids: LXXIV. 2,3-Dichloro- 4,4-ethylenedioxy-2-cyclopentenone in the Synthesis of Analogs of Marine Prostanoid

Transformations of readily accessible 2,3-dichloro-4,4-ethylenedioxy-2-cyclopentenone resulted in formation of previously unknown 2,3-dichloro-4-hydroxy-4-[(Z)-2-octenyl]-2-cyclopentenone which is a universal block synthon for analogs of marine prostanoids.     

Prostanoids. LXXVIII. New sp2-Functionalized 4-Hydroxy-2-cyclopentenones from 6,7-Dichloro-1,4-dioxaspiro[4.4]non-6-en-8-one

Readily accessible 6,7-dichloro-1,4-dioxaspiro[4.4]non-6-en-8-one was converted into 2,3-dichloro-, 2-ethylthio-, and 3-chloro-2-ethylthio-4-hydroxy-2-cyclopentenones.     

Reactions of 2,3,5-trichloro-4,4-ethylenedioxy-2-cyclopentenone with some ambident nucleophiles. Sterically loaded functionalized 6-azabicyclo[3.1.0]hex-5-enes

2,3,5-Trichloro-4,4-ethylenedioxy-2-cyclopentenone reacted with sodium azide in tetrahydrofuran to give the expected 3-azido derivative which was converted into 1,3-dichloro-4,4-ethylenedioxy-6-azabicyclo-[3.1.0]hex-5-en-2-one and 3-amino-2,5-dichloro-4,4-ethylenedioxy-2-cyclopentenone on heating in chloroform. The reaction of 2,3,5-trichloro-4,4-ethylenedioxy-2-cyclopentenone with potassium thiocyanate, depending on the conditions, afforded the corresponding 3-thiocyanato derivative or symmetric sulfide. Treatment of the title compound with hydroxylamine resulted in opening of the dioxolane ring with simultaneous formation of oxime via replacement of chlorine at the neighboring sp ²-carbon atom.Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 10, 2004, pp. 1569–1573.Original Russian Text Copyright © 2004 by Shavaleeva, Ivanova, Usmanova, Akhmetvaleev, Miftakhov.     

Synthesis and Stereochemistry of New N-Substituted Cytisine Derivatives

A series of new N-substituted cytisine derivatives was synthesized. The ¹ H and ¹³ C NMR spectra of certain compounds exhibit a doubled set of signals. This is explained by formation of diastereomeric pairs in compounds containing an asymmetric center in the substituents. The signal splitting in -COHC=CHCO ₂ H and HC=O (formyl) derivatives is explained by the existence of Z and E invertomers. Their stereochemical features are discussed. Amide conjugation is confirmed by temperature experiments.     

Synthesis of Dicobalt Hexacarbonyl Complex with B-Type 13,14-Didehydromisoprostol Analog

Russian Journal of Organic Chemistry - The reaction of dicobalt octacarbonyl with 8,12,13,14-tetradehydro-11-deoxymisoprostol analog and its trimethylsilyl ether afforded the corresponding dicobalt...     

Synthesis of 13,14-Dehydro-15-deoxy-16-hydroxy-16-methyl-17-phenoxyprostaglandin B1 Ethyl Ester

Russian Journal of Organic Chemistry - A new synthetic route has been developed for the construction of the main skeleton of ω-aryloxyprostaglandin (PG) via 1,2-addition of lithiated...     

Prostanoids: LXXXVIII. Chlorocyclopentenone Building Blocks in the Synthesis of Marine Prostanoids

Starting from 2,3-dichloro-4,4-ethylenedioxy-2-cyclopentenone, a practical procedure has been developed for the synthesis of a series of 4-substituted 2-chloro-4-hydroxycyclopentenones.     

Prostanoids: LXXVI. Synthesis and Specific Features of Reductive Dechlorination with the System Zn-NH4Cl-MeOH of Some 3-N-, O-, S-, Cl-, and Alkyl-substituted 2-Chloro-4,4-ethylenedioxycyclopent-2-en-1-ones Ozonolysis of 3-Caren-5-one

Reaction of a number of 3-N-, O-, S-, Cl-, and alkyl-substituted 2-chloro-4,4-ethylenedioxycyclopent-2-en-1-ones with Zn in NH₄Cl-MeOH medium were investigated.The expected or partially transformed dehydrochlorination products were isolated. An exclusive chemical stability of 3N-containing cyclopentenones was disclosed. This phenomenon was understood as originating from stabilizing n-d-p-interaction of electrons belonging to heteroatoms in the planar C¹(O)-C²(Cl)-C³ 3(N) fragment contained in the molecules of the compounds.