F. Huet

Monoacetals of α-Dicarbonyl Compounds from Enol Ethers

Abstract The title compounds which are interesting synthetic intermediates are now available by several recent methods, for instance: Double α-sulfenylation of carbonyl compounds or their derivatives, followed by exchange of thioalkyl (or thioaryl) groups by alkoxy groups(1) Alkylation of lithium derivatives of the imine or hydrazone of pyruvic aldehyde dimethyl acetal(2) Reaction of acetals of α-keto-esters(3) or α-keto-amides(4) with organometallic reagents

Use of alumina for elimination of sulfinic acid from β-aryl- and β-alkylsulfonyl carbonyl compounds

Abstract Title compounds give α-unsaturated carbonyl compounds by treatment with basic alumina in dichloromethane or diethylether. α-Enones are thus obtained in high yield at room temperature.

Concerning an unique intermediate in the formation of hydroperoxides and dioxetanes from monoolefins and singlet oxygen

Die isomeren Olefine (Ia) und (Ib) reagieren bei -50°C in Freon 12 mit sensibilisiertem Sauerstoff und anschliesender Reduktion mit Dimethylsulfid zu den Folgeprodukten (II)-(IV), in Abwesenheit des Reduktionsmittels erhalt man das Hydroperoxid (V) und das Dioxetan (VI).

Syntheses of nitrile and methyl ester corresponding to (dl)-sarkomycin and of related compounds

Abstract Nitrile 6a and ester 12 corresponding to (dl)-sarkomycin, 6- and 7-membered rings analogue nitriles 6b , 6c , and 3-methyl substituted nitrile 6d were prepared. Conjugate addition of cyanotrimethyl silane to cyclic α-enones gave 3-trimethylsiloxy 2-cycloalkene carbonitriles. Their alkylation with chloromethyl phenyl sulfide followed by oxone oxidation to sulfones and sulfinic acid elimination on basic alumina led to α-methylene carbonyl compounds. Obtention of the ester 12 involved acetalization of 3-oxo 2-phenylthiomethyl cyclopentane carbonitrile, basic hydrolysis into acid, deacetalization, estenfication, oxidation and elimination of sulfinic acid.

Comparaison du pouvoir reducteur des organolithiens a celui des reactifs de grignard dans des reactions vis-a-vis de composes carbonyles

Abstract Unlike i-BuMgX, which gives high ratios of reduction products in reactions with ketones, aldehydes and esters, i-BuLi gives almost exclusively addition products. Nearly similar results are obtained for the same reactions under Barbier type conditions. This enhancement of addition/reduction ratios from RMgX to RLi is also observed in addition of a linear hydrocarbon group, R, to a ketone.

O- and C-stannylation of nitroalkanes

Abstract Stannlylation of nitroalkanes by tributylstannyl amides and bis(tributylstannyl) or bis(triphenylstannyl) oxides has been found to give mainly tin nitronates. Some C -stannylated species have been also characterized.

Physics-based modelling of LiFePO 4 -graphite Li-ion batteries for power and capacity fade predictions: Application to calendar aging of PHEV and EV

In this paper, an isothermal physics-based aging model of Li-ion battery from the literature is modified and extended to predict both capacity and power fade of a commercial LiFePO4-graphite system. Compared to the isothermal reference mathematical framework, the present electrochemical and thermal model integrates the mechanism of porosity modification due to the SEI film growth into the negative electrode in order to propose theoretical correlations between capacity and power fade of the system. Based on the porous electrode theory, the aging model integrates different contributions of the cell impedance increase, such as the SEI film resistance and the electrolyte mass transport resistance due to the decrease of the negative electrode porosity. Experimental data coupling endurance tests and Electrochemical Impedance Spectroscopy (EIS) results, are used to validate the theoretical power and capacity fade correlations for calendar operating conditions. The model is then used to discuss the impact of calendar operating conditions on the aging and lifetime of PHEV and EV battery packs. Based on the simulation results, strategies are proposed to extend the battery life during the parking mode of the vehicle.