松下 亨 The present investigation was performed in order to clarify the mechanism of ataxic behavior following the administration of 2-(3-dimethylaminopropyl)-1,3,3a,4,9,9a-hexa hydro-4,9-o-benzeno-2H-benz[f]isoindole dimethiodide (MI-65-S) to mammals. For several years, many bis-quaternary ammonium salts containing a bicyclo(2.2.2) octane ring in their large cationic head have been synthesized in...

Identification of rigid counterparts for common flexible scaffolds is crucial to the advancement medicinal chemistry. Herein, synthesis new bicyclo[2.1.1]hexanes act as rigidified cyclopentanes described.

The cycloisomerization of 1,5-enynes catalyzed by cationic triphenylphosphinegold(I) complexes produces bicyclo[3.1.0]hexenes. Substitution at all positions of the 1,5-enyne is tolerated, leading to a wide range of bicyclo[3.1.0]hexane structures, including those containing quaternary carbons. Substrates containing a 1,2-disubstituted olefin undergo stereospecific cycloisomerization (cis-olefin...

A series of diverse natural product-like structures have been synthesised by the use of a number of novel transannulation reactions across a cyclononene ring. Transannular cyclisations through oxygen functionality have generated a number of bicyclo[5.3.1]systems containing bridged cyclic ethers and bicyclo[5.2.2]lactones, as well as a tetrahydrofuran-containing bridged analogue of hexacyclinic ...

The title compounds la—3c were prepared by stereoselective reduction of the respective dibromides. Pyrolysis gave allylic bromides (8, 9, 11) as primary and dienes (10, 12) as secondary products. Product ratios were independent of the stereochemistry of the starting materials. No differences of the rearrangement rates of the stereoisomers were observed in gas phase reactions of the derivatives ...

The stereoselective Diels-Alder reaction between an optically active 1,4-dimethylcycloheptadiene and acrolein was effectively promoted by TBSOTf to produce a bicyclo[3.2.2]nonene derivative bearing two quaternary carbons. Seven additional transformations from the obtained bicycle delivered the C 2-symmetric bicyclo[3.3.2]decene derivative, a key intermediate in our synthetic study of ryanodine.

Disproving a long C-C-bond textbook example: The reported 1.643 Å C-C bond in 5-cyano-1,3-dehydroadamantane was redetermined and "only" amounts to 1.584 Å. While this value is well reproduced with ab initio methods, some common DFT approaches perform poorly and are only consistent with CCSD(T)/cc-pVTZ optimizations for noninverted carbons. Large deviations from experiment were also found for ot...

In the presence of rat liver microsomes and NADPH n-loctene, n-4-octene and 3-ethyl-2-pentene were converted to the glycols with no trace of epoxides. Increased substitution of ethylenic hydxogen atoms by alkyl groups was found to retard. the rate of biological oxid.ation but to enhance that of epoxidation by perbenzoic acid. in chloroform. Microsomes without cofactors hydrolyzed the monosubsti...

Prostaglandins (PGs) are important mediators of macrophage activity, vascular permeability, fever, erythropoiesis, and proinflammatory responses to infection. Our recent studies have shown that plasma levels of bicyclo-PGE2 (a stable end product of PGE2 metabolism) and leukocyte cyclooxygenase (COX)-2 gene expression are suppressed in children with malarial anemia. Since the role of PGs as immu...