A new tandem cross enyne metathesis (CEYM)-intramolecular Diels-Alder reaction (IMDAR) has been carried out. It involves conjugated ketones, esters or amides bearing a remote olefin and aromatic alkynes as the starting materials. The overall process enables the preparation of a small family of linear bicyclic scaffolds in a very simple manner with moderate to good levels of diastereoselectivity...

A new reagent for the oxidation of hydrazones to diazo compounds is described. N-Iodo p-toluenesulfonamide (TsNIK, iodamine-T) allows the preparation of α-diazoesters, α-diazoamides, α-diazoketones and α-diazophosphonates in good yield and in high purity after a simple extractive work-up. α-Diazoesters were also obtained in high yield from the corresponding ketones through a one-pot process of ...

New 1,2,3-thiadiazole and 1,2,3-selenadiazole derivatives, 14-23, were prepared from the ketones 1-5 via the corresponding semicarbazones or hydrazones 6-12. The Hurd-Mori and Lalezari methods were used, respectively, for the preparation of these 1,2,3-thiadiazole and 1,2,3-selenadiazole derivatives. The intermediate 13 was also trapped, separated and fully characterized. These derivatives are ...

gem-dihydroperoxides as nearly stable peroxidic derivatives of aldehydes and ketones are known important intermediates in synthesis of anti-malaria drugs. also, because containing high concentration of peroxidic oxygen, recently, some of these compounds have been used as solid, efficient and powerful oxidants in many oxidation organic reactions. generally, these compounds are synthesized via pe...

We report the phospha-bora-Wittig reaction for direct preparation of phosphaalkenes from aldehydes, ketones, esters, or amides. The transient phosphaborene Mes*P?B–NR2 reacts with carbonyl compounds to form 1,2,3-phosphaboraoxetanes, analogues oxaphosphetane intermediates in classical Wittig reaction. 1,2,3-Phosphaboraoxetanes undergo thermal Lewis acid-promoted cycloreversion, yielding phospha...

The scope and limitation of the transformation of ketones to enones by selenenylation followed by selenoxide elimination have been examined. Several procedures for the preparation of a-phenylseleno ketones have been developed. The most useful are direct selenenylation of ketone enolates using PhSeBr and the reaction of enol acetates with electrophilic selenium species such as benzeneselenenyl t...