objective(s): the silver nanoparticles, being very small size, can permeate the cellular membrane and interfere in the cell's natural process. in the present study, the effects of time, the dosage of these particles and their use on blood molecules and hormones, the volume of drinking water, and the urine parameters were analyzed.materials and methods: thirty six rats of the wistar race, as sub...

Diels-Alder cycloaddition of 10 followed by Wittig homologation and intramolecular diene cyclozirconation of the resulting triene under equilibrating conditions led to the tricyclic 6-6-5 ketone 5 with high diastereocontrol. The derived alpha-azido ketone 16 cyclized efficiently to the heptacyclic pyrazine core of ritterazine N.

[structure: see text] Non-aldol aldol rearrangement of the epoxy silyl ether 13b afforded the expected anti methyl ketone 14, while the diastereomeric epoxy silyl ether 13a afforded the syn methyl ketone 8b via an unprecedented syn hydride migration. Calculations suggest that this unusual reaction proceeds via the carbocation, which cannot easily rotate due to steric hindrance.

The first synthesis of the sesquiterpene Lindenene is described. A novel non-catalysed intramolecular cyclopropanation reaction between a diazoketone and an unactivated alkene was utilised to construct the relatively labile ketone precursor with complete stereocontrol. This ketone was transformed in three steps into Lindenene.

The use of phenyl-2-pyridyl ketone oxime and di-2-pyridyl ketone oxime in Mn chemistry has led to hexanuclear clusters with unprecedented (Mn(II)(4)Mn(III)Mn(IV)) or extremely rare (Mn(II)Mn(III)(5) and Mn(II)(3)Mn(III)(3)) metal oxidation-state combinations and uncommon structural motifs.

A general synthetic approach to the isoprostanes has been established, based on intermolecular aldol condensation of a diazo ketone with an unsaturated aldehyde, followed by cyclization of the resulting diazo ketone to the cyclopropane. Subsequent kinetic opening with thiophenol followed by further elaboration then leads to the isoprostane. The history of this approach and the details of its de...

A new route to luminescent derivatives of androgenic steroids containing a ketone group in the 3- or 17-position has been developed. Reaction with the fac-Re(CO)(3)Cl complex of 3,3'-diamino-2,2'-bipyridine (complex 1) afforded a cyclic aminal product with different steroids. The rate of reaction and yield varies according to the conjugation or steric hindrance around the ketone group.