Dominique Fasseur

Decarboxylation of pyroglutamic acids with P2O5/CH3SO3H: a general synthesis of 5-aryl-2-pyrrolidinones

Abstract Treatment of pyroglutamic acids with acyl-activating reagents (P 2 O 5 /CH 3 SO 3 H, PPE ...), possibly in the presence of triethylamine, yields acyl iminium salts, that can react in-situ with aromatic compounds to give the corresponding 5-aryl-2-pyrrolidinones with good yields.

Reaction of trimethylsilyl derivatives with Meldrum's acid : A new and easy monofunctionalization of malonic acid

Abstract Treatment of Meldrums acid with silylated derivatives (amines, lactams or alcohols) yields very easily monofunctionalized malonic silyl esters. Hydrolysis of these silyl esters leads to the corresponding monoacids with a very good yield.

Studies on pyrrolidinones. On the decarboxylation of pyroglutamic acids and N-acyl prolines in acidic media

Abstract During attempted Friedel–Crafts cyclization of some arylmethyl pyroglutamic acids or of N-phenacyl prolines, decomposition of the activated form of the acid have been observed, giving new heterocyclic systems. This general decarboxylation occurred when there are difficulties to realize a Friedel–Crafts cyclization and is explained by geometrical or electronic considerations.

Reaction of Hexamethyldisilazane with Diacylhydrazines : An Easy 1,3,4-Oxadiazole Synthesis

Abstract The reaction of diacylhydrazines with hexamethyldisilazane in the presence of tetrabutylammonium fluoride as catalyst results in cyclisation to give 1,3,4-oxadiazoles in good yield.

Disilylated Compounds as Precursors of Heterocycles: A New and Easy Oxadiazole Synthesis

Abstract Silyl diacylhydtazines have been synthesized. When they are treated with 3 slight amount of a uariety of catalyst (nucleophiles, F, true or Lewis acids, Pd, Pt.), 1,3,4-oxadiazoles are obtained. This cyclization can be performed in one step by using hexamethyldisilazane or dimethyldichlorosilane as the silylation agent.

Acid Catalyzed Cyclization of Bis Silyl Diacylhydrazines: A New 1, 3, 4-Oxadiazole Synthesis

Abstract Diacylhydrazines are converted in good yields into 1,3,4-oxadiazoles with dichlorodimethyl-silane and trifluoromethane sulfonic acid.

Electrochemical synthesis of the vinylogs of N-acyl N,O-acetals and their reactivity

Abstract Vinylogs of N-acyl N,O-acetals are formed in good yields by anodic oxidation, in methanol or water, of β-enaminoesters derived from pyroglutamic acid. These new acetals react easily with nucleophiles or silylated amines.

Preparation of Pyrroles from Pyroglutamic Acid Derivatives

Abstract Heating of the vinylogs of N-acyl N,O-acetals 3 in acetic acid, preferably in the presence of acetic anhydride and pyridine, yields pyrroles 4 in good yields.