Synthesis of 4-substituted 3-oxabicyclo[3.1.0]hexan-2-one

Cyclopropanedicarboxylic acid anhydride can be converted to 4-substituted 3-oxabicyclo-[3.1.0]hexan-2-one by reaction with Grignard reagents in ether or tetrahydrofuran solution.     

Synthesis of prenyl diazoacetate and its intramolecular catalytic deazotization to 6,6-dimethyl-3-oxabicyclo[3.1.0]-hexan-2-one

Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2189–2190, September, 1990.     

Synthesis of cis-1,5-Dimethyl-2,4-dinitro-2,4-diazabicyclo[3.1.0]hexan-3-one and cis-1,5-dimethyl-2,4-dinitro-2,4-diazabicyclo[3.2.0]heptan-3-one

cis-1,5-Dimethyl-2,4-dinitro-2,4-diazabicyclo[3.2.0]heptan-3-one and cis-1,5-dimethyl-2,4-dinitro-2,4-diazabicyclo[3.1.0]hexan-3-one were both synthesized in three steps each from a common precursor, 1,3-diacetyl-4,5-dimelhyl-4-imidazolin-2-one.     

6-N-烷基-6-氮杂-2-氧代-3-氧杂-4-甲氧基-双环[3.1.0]己烷的合成、立体化学及抗癌活性研究

以3-溴-5-甲氧基-2(5H)-呋喃酮和伯胺为原料,在均相中用三乙胺作碱性催化剂,可以得到一对非对映异构体(1Z,4E,5Z)-6-N-烷基-6-氮杂-2-氧代-3-氧杂-4-甲氧基-双环[3.1.0]己烷(4)和(1Z,4Z,5Z)-6-N-烷基-6-氮杂-2-氧代-3-氧杂-4-甲氧基-双环[3.1.0]己烷(5).目标分子4和5经IR,1HNMR,13CNMR,EIMS进行了表征,并做了结肠癌细胞(HCT-8)、肝癌细胞(BEL-7402)、人胃癌细胞(BGC-823)、肺腺癌细胞(A549)和人卵巢癌细胞(A2780)的抗癌活性实验,其中5c和5d对HCT-8,BGC-823,A549和A2780等癌细胞有一定的抑制作用.此研究结果不仅丰富了该领域研究的理论基础,而且对某些新型药物的研制具有一定的指导意义.     

Synthesis of 3-acetylbicyclo[3.1.0]-2-hexen-4-one

Conclusions The synthesis of 3-acetylbicyclo[3.1.0]-2-hexen-4-one was accomplished.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2350–2352, October, 1972.     

Simple synthesis of substituted 3-oxabicyclo[3.1.0]hexan-2-ones and their rearrangement in the presence of lithium iodide

2-Alkenylidenemalonic ester monoepoxides react with organolithium and organomagnesium compounds to give 1-ethoxycarbonyl-4-alkyl-6-alkenyl(alkyl, aryl, alkynyl)-3-oxabicyclo[3.1.0]hexan-2-ones in high yields. The latter, when an alkenyl fragment is present, undergo rearrangement in the presence of LiI to substituted 1-ethoxycarbonyl-3-oxabicyclo[3.3.0]-6-octen-2-ones or 3-(1,3-butadienyl)-4-butanolides.Institute of Chemistry, Bashkir Science Center, Ural Branch, Russian Academy of Sciences, Ufa 450054. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 4, pp. 946–954, April, 1992.     

An efficient stereoselective synthesis of 4,5-trans-1,5-cis-3-oxabicyclo[3.1.0]hexan-2-ones via the iodolactonization of alkylidenecyclopropyl esters

[reaction: see text] A highly stereoselective iodolactonization of alkylidenecyclopropyl esters with iodine or N-iodosuccinimide (NIS) in aqueous CH3CN to afford 4,5-trans-1,5-cis-3-oxabicyclo-[3.1.0]hexane-2-ones is described. The reaction is very general, accommodating a wide range of substituents. A plausible mechanism that explains the essential role of water in this reaction is proposed.     

Conformational investigations of 6-EXO and 6-ENDO- methylbicyclo[3.1.0] hexan-3-one

R band (26.5–40 GHz) microwave spectra have been recorded for the common isotopic species of 6-endo-methylbicyclo[3.1.0]hexan-3-one and 6-exo-methylbicyclo[3.1.0]hexan-3-one. These spectra are shown to be consistent with a ground vibrational state boat conformation having five membered ring dihedral angles of 7.2 ± 0.3° and 20.5 ± 1.4° respectively. This information is correlated with product quantum yields obtained on photolysis of these molecules.     

Photochemistry of bis(2-methyl-1-propenyl)ether and 2,2,4,4-tetramethyl-6-oxabicyclo [3.1.0] hexan-3-one: on the search for the oxydi-π-methane rearrangement

π,π-Excitation of bis(2-methyl-1-propenyl)ether leads to products derived from a vinyl-vinyloxy radical pair; photochemical decarbonylation (n,π) of the title ketone provides an entry into the diradical manifold of the oxydi-π-methane rearrangement.     

Asymmetric synthesis of 4-ethoxy-1-p-tolylsulfonyl-3,6-dioxabicyclo[3.1.0]hexan-2-ones

Optically pure sulfinylfuranones undergo oxidation at sulfur followed by a totally stereoselective epoxidation at the electron deficient double bond by treatment with MCPBA at room temperature to afford, in good yields, enantiomerically pure 4-ethoxy-5-alkyl-1-p-tolylsulfonyl-3,6-dioxabicyclo[3.1.0]hexan-2-ones. These epoxyfuranones are obtained along with cyclopropanefuranones by reaction of 4-ethoxy-6-p-tolylsulfinylfuro[3,4-c]pyrazolin-6-ones with MPCBA. In both cases, the formation of the sulfonyl epoxylactones takes place by oxidation of the sulfonylfuran-2(5H)-one resulting from the starting materials. This reaction is completely stereoselective (controlled by the configuration of C-5 of furanone) and results from the nucleophilic attack of the peroxycarboxylate generated by interaction of the reagent with weak basic centres at the substrates.     

Synthesis of dicyclopropanes from 4,7,7-Trimethyl-3-oxabicyclo[4.1.0]hept-4-en-2-one

New optically active dicyclopropanes were synthesized on the basis of transformation products of 4,7,7-trimethyl-3-oxabicyclo[4.1.0]hept-4-en-2-one using dichlorocarbene or sulfoxonium ylide in the key cyclopropanation stages.     

Stereochemical assignments of the 6-phenyl-2-oxabicyclo[3.1.0]hexanes

Preparation and stereochemical assignments of the 6-phenyl-2-oxabicyclo[3.1.0]hexanes are reported. The stereochemical assignments are based on chemical as well as nmr data.     

Enantioselective synthesis of bicyclo[6.1.0]nonane-9-carboxylic acids via Me2AlOTf-promoted intramolecular Friedel-Crafts alkylation of arenes with the gamma-lactone moiety of 3-oxabicyclo[3.1.0]hexan-2-ones

A strategy to rapidly assemble enantiomerically pure bicyclo[6.1.0]nonane-9-carboxylic acids via Me2AlOTf-promoted intramolecular Friedel-Crafts alkylation of tethered pi-nucleophiles with the gamma-lactone moiety of 3-oxabicyclo[3.1.0]hexan-2-ones is described. The approach begins with the enantioselective synthesis of 3-oxabicyclo[3.1.0]hexan-2-ones bearing a tethered pi-nucleophile at the 6-position by intramolecular Rh(II)-catalyzed cyclopropanation of allylic diazoacetates, prepared from the corresponding (Z)-allylic alcohols. Me2AlOTf-induced intramolecular Friedel-Crafts cyclization provides medium-sized carbocycles and heterocycles in high yields without requiring high-dilution or slow substrate addition techniques. The scope and limitations of this synthetic methodology are presented.