Sylvestre Julia

A direct synthesis of olefins by reaction of carbonyl compounds with lithio derivatives of 2-[alkyl- or (2′-alkenyl)- or benzyl-sulfonyl]-benzothiazoles.

Abstract During the title reaction, the lithium alkoxides formed as intermediates undergo an intramolecular addition to the neighboring CN group followed an S to 0 benzothiazole transfer and simultaneous extrustion of sulfur dioxide and ejection of 2(3H)-benzothiazolone anion.

Reactivite des carbenes et carbenoides issus de diazomalonates mixtes de methyle et de benzyles substitues. Synthese de composes cycloheptatrieniques

The title diazomalonates, when treated with copper powder in octane, yield lactones of 1-hydroxymethyl 7-carboxy cycloheptatrienes. The yields of cyclisation product from such diazoesters may be increased either by a gem-dimethyl grouping or by an electron rich mesomeric group attached to the benzene ring. The methoxy-cycloheptatriene compound 3d is hydrolysed to the spirodienone 8. The carbenes formed from the diazomalonates 2a and b by photolysis or thermolysis undergo Wolff rearrangement and yield insertion products into CH bonds of solvent.

Reactivity of the 1-t.butylthio-3-methoxy-1-alkenes towards metalating agents. I: Regioselective deprotonation at either one of the two olefinic sites of the Z-isomers

Abstract THF solutions of the title Z-isomers (with the exception of the propenyl compound) at −78° produce either (i) the 1-metalated derivatives when treated with potassium t.butoxide and n.butyllithium or (ii) the 2-lithiated derivatives when sec.butyllithium is the metalating agent. Both metalated derivatives become new equivalents of the hypothetical anions I and II respectively.

Asymmetric Catalytic Epoxydation by Means of Cyclodextrins

Abstract Asymmetric synthesis occurs in the epoxidation of trans-chalcone with sodium hypochlorite and cyclodextrins, with enantiomeric excess up to 11%.

Rearrangements sigmatropiques [2.3] d'organomagnesiens formes par action de derives de grignard sur des dithioesters S-allyliques diversement substitues; synthese de dithioacetals de cetones β-ethyleniques

Abstract Dithioacetals of β-unsaturated ketones are obtained, by thiophilic addition of Grignard reagents to S-allylic dithioesters in tetrahydrofuran at low temperatures, followed by [2.3] sigmatropic rearrangement of the intermediate carbanion and methylation.

N-aryl-ethenesulphenamides; thermal transformation of two N-)1-naphthyl)-ethenesulphenamides into 1H-benz[g]indoles

Abstract Reaction of vinylmagnesium bromide with morpholine or piperidine-N-sulphenyl chlorides 3a , b affords the N-ethenylthio-morpholine and -piperidine 4a , b . When treated with stoichiometric amounts of an arylamine and methanesulphonic (or trifluoroacetic) acid, the sulphenamides 4 are converted into N-aryl-ethenesulphenamides 6a - e . On heating in toluene, two of these sulphenamides 6d and 6e undergo [3.3]-sigmotropic rearrangements followed by cyclisation of the intermediate amino-thioaldehydes yielding the corresponding 1H-benz[g]indoles 8a , b .

Unsaturated sulfinamides III. Conversion of several 4-(2'-alkenesulfinyl)-morpholines into the corresponding sulfinate esters, unsymmetrical bisallylic sulfones and olefins. isolation of some functionalised 2-alkenesulfinic acids

The boron trifluoride etherate-catalysed treatment of the unsaturated sulfinamides (1a–1e) with simple saturated alcohols afforded the corresponding alkyl sulfinates 2 whereas allylic alcohols provided the bisallylic sulfones 4. Efficient conditions for the acid-catalysed hydrolysis of the unsaturated sulfinamides 1 are described and some allylic sulfinic acids bearing an electron-withdrawing group 6 were isolated. Smooth fragmentation of the homoconjugated sulfinic acids gave the corresponding olefins 5 and 7.

Synthesis of indoles from N-aryl-1-alkenylsulphinamides

Abstract Reaction of 1-alkenylmagnesium bromides with N-sulphinyl-benzenamines affords the title sulphinamides 5 . On heating in toluene, these sulphinamides 5 are transformed into the corresponding indoles.

Substituted 4-(1′,2′-alkadienesulphinyl)-morpholines; preparation and hydrolytic desulphinylation into the corresponding alkynes

By the reaction with 4-morpholinesulphenyl chloride carried out in the presence of triethylamine, several substituted propargylic alcohols have been converted into the corresponding allenic sulphinamides 2. As a complementary method, the new allenic lithio-derivatives II have been prepared and efficiently alkylated with organic halides. The acid-catalysed hydrolysis or deuterolysis of the title sulphinamides 2 provide the corresponding alkynes.

Reactivity of the 1-t.butylthio-3-methoxy-1-alkenes towards metalating agents. II: Allylic deprotonation of the E-isomers and of the Z-propenyl derivative

Abstract Deprotonation of the title compounds with a lithiating agent and subsequent alkylation furnish the 1-substituted products 4 . The 1-t.butylthio-3-methoxy-1-lithio-1-alkenes 3 become new equivalents of the hypothetical anions I.