Giovanni Piancatelli

Oxidative ring opening of furan derivatives to α,β-unsaturated γ-dicarbonyl compounds, useful intermediates for 3-oxocyclopentenes synthesis

Abstract α,β-unsaturated γ-dicarbonyl compounds, easily obtained by reaction of pyridinium chlorochromate with alkylfurans, are interesting starting materials for the rapid synthesis of 3-oxo-cyclopentenes.

A new synthesis of 3-oxocyclopentenes

Abstract 5 - Methyl - 2 - furylcarbinols 3 have been converted into 3-oxocyclopentene derivatives 4 through a molecular rearrangement catalyzed by ZnCl 2 . The reaction mechanism is explained in terms of a thermal electrocyclic reaction of a 4π electrons system. An application relative to the synthesis of (±) allethrolone is reported. reported.

Mercuration-reductive demercuration of glycals: A mild and convenient entry to 2-deoxy-sugars

Abstract Protected glycals, derived from mono-, di- and tri-saccharides, were easily and efficiently converted into the corresponding 2-deoxy-sugars, by reaction with mercuric(II) acetate/sodium borohydride in a polar solvent at 0 °C. The mild and non acidic reaction conditions permit the survival of acid-labile groups, such as silyl ethers.

Asymmetric carbolithiation of 2-phenylselenofumarate derivatives: a short synthesis of (−)-roccellaric acid

Abstract (−)-Roccellaric acid and variously substituted succinates are obtained through direct asymmetric carbolithiation of 2-phenylselenofumarate derivatives, followed by reaction with suitable electrophiles.

Radical Additions to Olefins in the Presence of Iodobenzenediacetate: an Easy Route to Alkyl Dithiocyanates

Abstract We describe a new application of iodobenzenediacetate (IBDA), which is able to oxidize thiocyanate anion to the corresponding radical. Subsequent addition to nucleophilic olefins leads to dithiocyanate derivatives. The radical addition to olefins is more effective when performing the thiocyanation reaction in presence of Mg(ClO 4 ) 2 or TEMPO.

The binary reagent PhI(OAc)2-Mg(CIO4)2:a SET induced ring enlargement of furan derivatives into pyranones

Abstract The binary reagent PhI(OAc) 2 -Mg(CIO 4 ) 2 is very efficient for a high conversion of (2-furyl)-1-alcohols into pyranones. The reaction mechanism can be explained in terms of a SET process, with the generation of a cation radical as key intermediate.

2-Deoxy-disaccharide approach to natural and unnatural glycosphingolipids synthesis

Abstract 2-Deoxy-disaccharides were easily converted into glycosylphytosphingosines, as new and efficient precursors of natural and unnatural glycosphingolipids.

Hypervalent iodine chemistry: Novel and direct thiocyanation of alkenes using [bis(acetoxy)iodo]benzene/trimethylsilyl isothiocyanate reagent combination. Synthesis of 1,2-dithiocyanates

Abstract Novel and direct thiocyanation of alkenes using [bis(acetoxy)iodo]benzene/trimethylsilyl isothiocyanate reagent combination has been developed.

General route and mechanism of the rearrangement of the 4-substituted 5-hydroxy-3-oxocyclopentenes into the 2-substituted analogs

Abstract A general method of synthesis of hydroxycyclopentenones of type 6 starting from the isomeric compound 2 is described. This conversion is shown to occur through an alumina-catalyzed process of intramolecular hydration.

Pyridinium dichromate in organic synthesis: a convenient oxidation of olefin-iodine complexes to α-iodo ketones

Cyclic α-iodo ketones are obtained directly by oxidation of olefin-iodine complexes with pyridinium dichromate.