Syntheses based on 8-substituted 3-bromoacetyl-3,8-dimethyl-2,7-dioxaspiro[4,4]nonane-1,6-diones

By reaction of 8-substituted 3-bromoacetyl-3,8-dimethyl-2,7-dioxaspiro[4,4]nonane-1,6-diones with thiourea and substituted thioureas under Hansch reaction conditions, we have obtained the novel heterocycles 3-[2′-amino(arylamino)thiazol-4-yl]-3,8-dimethyl-2,7-dioxaspiro[4,4]nonane-1,6-diones. By reacting the above-indicated bromoacetyl spirodilactones with 5-aryl-3-mercapto-1,2,4-triazoles, we obtained 8-substituted 3-(aryl-3,8-dimethyl-1′,2′,4′-triazol-3′-yl)thioacetyl-2,7-dioxaspiro[4,4]nonane-1,6-diones. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 123–129, January, 2006.     

Synthesis of 1,2,4-triazole-3-thiols and their S-substituted derivatives

New 1,2,4-triazole-3-thiols were synthesized by reactions of the corresponding carboxylic acid hydrazides with isothiocyanates and subsequent cyclization of intermediate 1,4-substituted thiosemicarbazides. Alkylation of 1,2,4-triazole-3-thiols with benzyl chlorides and bromacetophenones gave only S-substituted derivatives.     

Synthesis of new 6,7-dihydro-1H-cyclopenta[d]pyrimidine-2,4(3H,5H)-dione derivatives containing the substituted aliphatic ring

The bromination of 6,7-dihydro-1H-cyclopenta[d]pyrimidine-2,4(3H,5H)-dione (1) resulted in the substitution in the aliphatic ring. The reaction of this product with different N-nucleophiles gives new derivatives of the starting compound. The direction of the substitution in the alicycle was established by studying further transformations of some of these compounds by means of NMR spectroscopy.     

New Synthesis of 2-Acetonyl-4-alkoxymethylbutanolide

A new method was developed for synthesis of 2-acetonyl-4-alkoxymethylbutanolides by treatment of 4-alkoxymethyl-2-(-chloroallyl)butanolides with concentrated sulfuric acid and subsequent hydrolysis. 4-alkoxymethyl-2-(-chloroallyl)butanolides are readily obtained by alkylation of accessible 4-alkoxymethyl-2-ethoxycarbonylbutanolides with 2,3-dichloropropene, followed by hydrolysis and decarboxylation of the resulting 4-alkoxymethyl-2-(-chloroallyl)-2-ethoxycarbonylbutanolides.     

Synthesis and Some Transformations of 4-Alkoxymethyl-2-ethoxycarbonyl-2-ethoxycarbonylmethylbutanolides

A method was developed for the production of 4-alkoxy-2-ethoxycarbonyl-2-ethoxycarbonylmethylbutanolides. The latter were subjected to alkaline and acid hydrolysis, leading to 4-alkoxymethyl-2-carboxymethylbutanolides, from which lactone-containing thioureas and amides of carboxylactones with novel structures were obtained. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1625–1633, November, 2005.     

Synthesis of 5-substituted 3-(2-oxopropyl)tetrahydrofuran-2-ones and heterocyclic compounds on their base

Alkylation of ethyl 2-oxotetrahydrofuran-3-carboxylates with 2,3-dichloroprop-1-ene and 3-bromoprop-1-yne gave new 3,5,5-tri- and 3,3,5,5-tetrasubstituted tetrahydrofuran-2-ones which were converted into the corresponding 3-(2-oxopropyl)tetrahydrofuran-2-ones. Reactions of the latter with semicarabazide, thiosemicarbazide, and phenylhydrazine were studied with a view to obtain new heterocyclic lactones.     

Synthesis and Some Transformations of Ethyl 5-Alkoxymethyl-3-(2-methyl-3-oxobutyl)-2-oxotetrahydrofuran-3-carboxylates

Michael reaction of ethyl 5-alkoxymethyl-2-oxotetrahydrofuran-3-carboxylates with 3-methyl-3-buten-2-one gave ethyl 5-alkoxymethyl-3-(2-methyl-3-oxobutyl)-2-oxotetrahydrofuran-3-carboxylates. Alkaline hydrolysis of the latter, followed by decarboxylation afforded 5-alkoxymethyl-3-(2-methyl-3-oxobutyl)tetrahydrofuran-2-ones. The bromination of ethyl 5-alkoxymethyl-3-(2-methyl-3-oxobutyl)-2-oxotetrahydrofuran-3-carboxylates provides a convenient method for the preparation of 3-acetyl-8-alkoxymethyl-3-methyl- and 8-alkoxymethyl-3-bromoacetyl-3-methyl-2,7-dioxaspiro[4.4]nonane-1,6-diones in high yields.     

Synthesis of Carboxylactones and New Heterocyclic Compounds

The Michael reaction of 2‐ethoxycarbonyl‐4‐alkoxymethylbutanolides with methyl acrylate affords esterolactones in high yields. Alkaline hydrolysis of the latter resulted in carboxylactones that were transformed into ethyl α‐bromolactonoesters. The reactions of the latter with thiourea and arylthioureas result in heterocyclic compounds of an original structure joint with a butanolide ring.     

Synthesis of new α-spiroheteryl-fused butanolides

4-Alkoxymethyl-2-bromo-2-ethoxycarbonylbutanolides were obtained with good yields by the bromination of 4-alkoxymethyl-2-ethoxycarbonylbutanolides with bromine in dry carbon tetrachloride. Reaction of the products with thiourea and aryl-substituted thioureas gave spiroheteryl-fused lactones of a new generation-8-alkoxymethyl-3-amino(arylamino)-7-oxa-4-thia-2-azaspiro[4,4]-2-nonene-1,6-diones. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 510–514, April, 2006.