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.

Kişinin soyadı üzerindeki hakkı, Türkiye Cumhuriyeti Anayasası’yla ve Türkiye’nin de taraf olduğu milletlerarası sözleşmelerle koruma altına alınmış, vazgeçilemez, devredilemez, kişiye sıkı sıkıya bağlı bir hak niteliği taşımaktadır. 743 sayılı Türk Kanunu Medenisi döneminden bu yana evlilik birliği içindeki kadının, kocasının soyadını taşıması yasal zorunluluk olarak düzenlenmiştir. Kadınların...

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.